chore: regens API reference docs (#889)

diff --git a/docs/dyn/vault_v1.matters.holds.html b/docs/dyn/vault_v1.matters.holds.html
index 43d65c2..fd92312 100644
--- a/docs/dyn/vault_v1.matters.holds.html
+++ b/docs/dyn/vault_v1.matters.holds.html
@@ -80,10 +80,10 @@
 <p class="firstline">Returns the accounts Resource.</p>
 
 <p class="toc_element">
-  <code><a href="#addHeldAccounts">addHeldAccounts(matterId, holdId, body, x__xgafv=None)</a></code></p>
+  <code><a href="#addHeldAccounts">addHeldAccounts(matterId, holdId, body=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Adds HeldAccounts to a hold. Returns a list of accounts that have been</p>
 <p class="toc_element">
-  <code><a href="#create">create(matterId, body, x__xgafv=None)</a></code></p>
+  <code><a href="#create">create(matterId, body=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Creates a hold in the given matter.</p>
 <p class="toc_element">
   <code><a href="#delete">delete(matterId, holdId, x__xgafv=None)</a></code></p>
@@ -98,14 +98,14 @@
   <code><a href="#list_next">list_next(previous_request, previous_response)</a></code></p>
 <p class="firstline">Retrieves the next page of results.</p>
 <p class="toc_element">
-  <code><a href="#removeHeldAccounts">removeHeldAccounts(matterId, holdId, body, x__xgafv=None)</a></code></p>
+  <code><a href="#removeHeldAccounts">removeHeldAccounts(matterId, holdId, body=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Removes HeldAccounts from a hold. Returns a list of statuses in the same</p>
 <p class="toc_element">
-  <code><a href="#update">update(matterId, holdId, body, x__xgafv=None)</a></code></p>
+  <code><a href="#update">update(matterId, holdId, body=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Updates the OU and/or query parameters of a hold. You cannot add accounts</p>
 <h3>Method Details</h3>
 <div class="method">
-    <code class="details" id="addHeldAccounts">addHeldAccounts(matterId, holdId, body, x__xgafv=None)</code>
+    <code class="details" id="addHeldAccounts">addHeldAccounts(matterId, holdId, body=None, x__xgafv=None)</code>
   <pre>Adds HeldAccounts to a hold. Returns a list of accounts that have been
 successfully added. Accounts can only be added to an existing account-based
 hold.
@@ -113,11 +113,11 @@
 Args:
   matterId: string, The matter ID. (required)
   holdId: string, The hold ID. (required)
-  body: object, The request body. (required)
+  body: object, The request body.
     The object takes the form of:
 
 { # Add a list of accounts to a hold.
-    "accountIds": [ # Account ids to identify which accounts to add. Only account_ids or only
+    "accountIds": [ # Account IDs to identify which accounts to add. Only account_ids or only
         # emails should be specified, but not both.
       "A String",
     ],
@@ -141,56 +141,11 @@
           # HeldAccount, if successful.
         "status": { # The `Status` type defines a logical error model that is suitable for # This represents the success status. If failed, check message.
             # different programming environments, including REST APIs and RPC APIs. It is
-            # used by [gRPC](https://github.com/grpc). The error model is designed to be:
+            # used by [gRPC](https://github.com/grpc). Each `Status` message contains
+            # three pieces of data: error code, error message, and error details.
             #
-            # - Simple to use and understand for most users
-            # - Flexible enough to meet unexpected needs
-            #
-            # # Overview
-            #
-            # The `Status` message contains three pieces of data: error code, error
-            # message, and error details. The error code should be an enum value of
-            # google.rpc.Code, but it may accept additional error codes if needed.  The
-            # error message should be a developer-facing English message that helps
-            # developers *understand* and *resolve* the error. If a localized user-facing
-            # error message is needed, put the localized message in the error details or
-            # localize it in the client. The optional error details may contain arbitrary
-            # information about the error. There is a predefined set of error detail types
-            # in the package `google.rpc` that can be used for common error conditions.
-            #
-            # # Language mapping
-            #
-            # The `Status` message is the logical representation of the error model, but it
-            # is not necessarily the actual wire format. When the `Status` message is
-            # exposed in different client libraries and different wire protocols, it can be
-            # mapped differently. For example, it will likely be mapped to some exceptions
-            # in Java, but more likely mapped to some error codes in C.
-            #
-            # # Other uses
-            #
-            # The error model and the `Status` message can be used in a variety of
-            # environments, either with or without APIs, to provide a
-            # consistent developer experience across different environments.
-            #
-            # Example uses of this error model include:
-            #
-            # - Partial errors. If a service needs to return partial errors to the client,
-            #     it may embed the `Status` in the normal response to indicate the partial
-            #     errors.
-            #
-            # - Workflow errors. A typical workflow has multiple steps. Each step may
-            #     have a `Status` message for error reporting.
-            #
-            # - Batch operations. If a client uses batch request and batch response, the
-            #     `Status` message should be used directly inside batch response, one for
-            #     each error sub-response.
-            #
-            # - Asynchronous operations. If an API call embeds asynchronous operation
-            #     results in its response, the status of those operations should be
-            #     represented directly using the `Status` message.
-            #
-            # - Logging. If some API errors are stored in logs, the message `Status` could
-            #     be used directly after any stripping needed for security/privacy reasons.
+            # You can find out more about this error model and how to work with it in the
+            # [API Design Guide](https://cloud.google.com/apis/design/errors).
           "message": "A String", # A developer-facing error message, which should be in English. Any
               # user-facing error message should be localized and sent in the
               # google.rpc.Status.details field, or localized by the client.
@@ -210,7 +165,7 @@
               # precedence over account ID.
           "firstName": "A String", # Output only. The first name of the account holder.
           "accountId": "A String", # The account's ID as provided by the
-              # <a href="https://developers.google.com/admin-sdk/">Admin SDK</a>.
+              # &lt;a href="https://developers.google.com/admin-sdk/"&gt;Admin SDK&lt;/a&gt;.
         },
       },
     ],
@@ -218,12 +173,12 @@
 </div>
 
 <div class="method">
-    <code class="details" id="create">create(matterId, body, x__xgafv=None)</code>
+    <code class="details" id="create">create(matterId, body=None, x__xgafv=None)</code>
   <pre>Creates a hold in the given matter.
 
 Args:
   matterId: string, The matter ID. (required)
-  body: object, The request body. (required)
+  body: object, The request body.
     The object takes the form of:
 
 { # Represents a hold within Vault. A hold restricts purging of
@@ -249,7 +204,7 @@
           # precedence over account ID.
       "firstName": "A String", # Output only. The first name of the account holder.
       "accountId": "A String", # The account's ID as provided by the
-          # <a href="https://developers.google.com/admin-sdk/">Admin SDK</a>.
+          # &lt;a href="https://developers.google.com/admin-sdk/"&gt;Admin SDK&lt;/a&gt;.
     },
   ],
   "query": { # Corpus specific queries. # The corpus-specific query. If set, the corpusQuery must match corpus
@@ -312,7 +267,7 @@
             # precedence over account ID.
         "firstName": "A String", # Output only. The first name of the account holder.
         "accountId": "A String", # The account's ID as provided by the
-            # <a href="https://developers.google.com/admin-sdk/">Admin SDK</a>.
+            # &lt;a href="https://developers.google.com/admin-sdk/"&gt;Admin SDK&lt;/a&gt;.
       },
     ],
     "query": { # Corpus specific queries. # The corpus-specific query. If set, the corpusQuery must match corpus
@@ -411,7 +366,7 @@
             # precedence over account ID.
         "firstName": "A String", # Output only. The first name of the account holder.
         "accountId": "A String", # The account's ID as provided by the
-            # <a href="https://developers.google.com/admin-sdk/">Admin SDK</a>.
+            # &lt;a href="https://developers.google.com/admin-sdk/"&gt;Admin SDK&lt;/a&gt;.
       },
     ],
     "query": { # Corpus specific queries. # The corpus-specific query. If set, the corpusQuery must match corpus
@@ -491,7 +446,7 @@
                 # precedence over account ID.
             "firstName": "A String", # Output only. The first name of the account holder.
             "accountId": "A String", # The account's ID as provided by the
-                # <a href="https://developers.google.com/admin-sdk/">Admin SDK</a>.
+                # &lt;a href="https://developers.google.com/admin-sdk/"&gt;Admin SDK&lt;/a&gt;.
           },
         ],
         "query": { # Corpus specific queries. # The corpus-specific query. If set, the corpusQuery must match corpus
@@ -541,7 +496,7 @@
 </div>
 
 <div class="method">
-    <code class="details" id="removeHeldAccounts">removeHeldAccounts(matterId, holdId, body, x__xgafv=None)</code>
+    <code class="details" id="removeHeldAccounts">removeHeldAccounts(matterId, holdId, body=None, x__xgafv=None)</code>
   <pre>Removes HeldAccounts from a hold. Returns a list of statuses in the same
 order as the request. If this request leaves the hold with no held
 accounts, the hold will not apply to any accounts.
@@ -549,11 +504,11 @@
 Args:
   matterId: string, The matter ID. (required)
   holdId: string, The hold ID. (required)
-  body: object, The request body. (required)
+  body: object, The request body.
     The object takes the form of:
 
 { # Remove a list of accounts from a hold.
-    "accountIds": [ # Account ids to identify HeldAccounts to remove.
+    "accountIds": [ # Account IDs to identify HeldAccounts to remove.
       "A String",
     ],
   }
@@ -571,56 +526,11 @@
         # same order as the request.
       { # The `Status` type defines a logical error model that is suitable for
           # different programming environments, including REST APIs and RPC APIs. It is
-          # used by [gRPC](https://github.com/grpc). The error model is designed to be:
+          # used by [gRPC](https://github.com/grpc). Each `Status` message contains
+          # three pieces of data: error code, error message, and error details.
           #
-          # - Simple to use and understand for most users
-          # - Flexible enough to meet unexpected needs
-          #
-          # # Overview
-          #
-          # The `Status` message contains three pieces of data: error code, error
-          # message, and error details. The error code should be an enum value of
-          # google.rpc.Code, but it may accept additional error codes if needed.  The
-          # error message should be a developer-facing English message that helps
-          # developers *understand* and *resolve* the error. If a localized user-facing
-          # error message is needed, put the localized message in the error details or
-          # localize it in the client. The optional error details may contain arbitrary
-          # information about the error. There is a predefined set of error detail types
-          # in the package `google.rpc` that can be used for common error conditions.
-          #
-          # # Language mapping
-          #
-          # The `Status` message is the logical representation of the error model, but it
-          # is not necessarily the actual wire format. When the `Status` message is
-          # exposed in different client libraries and different wire protocols, it can be
-          # mapped differently. For example, it will likely be mapped to some exceptions
-          # in Java, but more likely mapped to some error codes in C.
-          #
-          # # Other uses
-          #
-          # The error model and the `Status` message can be used in a variety of
-          # environments, either with or without APIs, to provide a
-          # consistent developer experience across different environments.
-          #
-          # Example uses of this error model include:
-          #
-          # - Partial errors. If a service needs to return partial errors to the client,
-          #     it may embed the `Status` in the normal response to indicate the partial
-          #     errors.
-          #
-          # - Workflow errors. A typical workflow has multiple steps. Each step may
-          #     have a `Status` message for error reporting.
-          #
-          # - Batch operations. If a client uses batch request and batch response, the
-          #     `Status` message should be used directly inside batch response, one for
-          #     each error sub-response.
-          #
-          # - Asynchronous operations. If an API call embeds asynchronous operation
-          #     results in its response, the status of those operations should be
-          #     represented directly using the `Status` message.
-          #
-          # - Logging. If some API errors are stored in logs, the message `Status` could
-          #     be used directly after any stripping needed for security/privacy reasons.
+          # You can find out more about this error model and how to work with it in the
+          # [API Design Guide](https://cloud.google.com/apis/design/errors).
         "message": "A String", # A developer-facing error message, which should be in English. Any
             # user-facing error message should be localized and sent in the
             # google.rpc.Status.details field, or localized by the client.
@@ -637,7 +547,7 @@
 </div>
 
 <div class="method">
-    <code class="details" id="update">update(matterId, holdId, body, x__xgafv=None)</code>
+    <code class="details" id="update">update(matterId, holdId, body=None, x__xgafv=None)</code>
   <pre>Updates the OU and/or query parameters of a hold. You cannot add accounts
 to a hold that covers an OU, nor can you add OUs to a hold that covers
 individual accounts. Accounts listed in the hold will be ignored.
@@ -645,7 +555,7 @@
 Args:
   matterId: string, The matter ID. (required)
   holdId: string, The ID of the hold. (required)
-  body: object, The request body. (required)
+  body: object, The request body.
     The object takes the form of:
 
 { # Represents a hold within Vault. A hold restricts purging of
@@ -671,7 +581,7 @@
           # precedence over account ID.
       "firstName": "A String", # Output only. The first name of the account holder.
       "accountId": "A String", # The account's ID as provided by the
-          # <a href="https://developers.google.com/admin-sdk/">Admin SDK</a>.
+          # &lt;a href="https://developers.google.com/admin-sdk/"&gt;Admin SDK&lt;/a&gt;.
     },
   ],
   "query": { # Corpus specific queries. # The corpus-specific query. If set, the corpusQuery must match corpus
@@ -734,7 +644,7 @@
             # precedence over account ID.
         "firstName": "A String", # Output only. The first name of the account holder.
         "accountId": "A String", # The account's ID as provided by the
-            # <a href="https://developers.google.com/admin-sdk/">Admin SDK</a>.
+            # &lt;a href="https://developers.google.com/admin-sdk/"&gt;Admin SDK&lt;/a&gt;.
       },
     ],
     "query": { # Corpus specific queries. # The corpus-specific query. If set, the corpusQuery must match corpus