chore: regens API reference docs (#889)

diff --git a/docs/dyn/cloudbilling_v1.projects.html b/docs/dyn/cloudbilling_v1.projects.html
index 536d053..745f610 100644
--- a/docs/dyn/cloudbilling_v1.projects.html
+++ b/docs/dyn/cloudbilling_v1.projects.html
@@ -78,7 +78,7 @@
   <code><a href="#getBillingInfo">getBillingInfo(name, x__xgafv=None)</a></code></p>
 <p class="firstline">Gets the billing information for a project. The current authenticated user</p>
 <p class="toc_element">
-  <code><a href="#updateBillingInfo">updateBillingInfo(name, body, x__xgafv=None)</a></code></p>
+  <code><a href="#updateBillingInfo">updateBillingInfo(name, body=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Sets or updates the billing account associated with a project. You specify</p>
 <h3>Method Details</h3>
 <div class="method">
@@ -89,7 +89,7 @@
 ).
 
 Args:
-  name: string, The resource name of the project for which billing information is
+  name: string, Required. The resource name of the project for which billing information is
 retrieved. For example, `projects/tokyo-rain-123`. (required)
   x__xgafv: string, V1 error format.
     Allowed values
@@ -105,21 +105,21 @@
     "projectId": "A String", # The ID of the project that this `ProjectBillingInfo` represents, such as
         # `tokyo-rain-123`. This is a convenience field so that you don't need to
         # parse the `name` field to obtain a project ID. This field is read-only.
-    "name": "A String", # The resource name for the `ProjectBillingInfo`; has the form
-        # `projects/{project_id}/billingInfo`. For example, the resource name for the
-        # billing information for project `tokyo-rain-123` would be
-        # `projects/tokyo-rain-123/billingInfo`. This field is read-only.
+    "billingAccountName": "A String", # The resource name of the billing account associated with the project, if
+        # any. For example, `billingAccounts/012345-567890-ABCDEF`.
     "billingEnabled": True or False, # True if the project is associated with an open billing account, to which
         # usage on the project is charged. False if the project is associated with a
         # closed billing account, or no billing account at all, and therefore cannot
         # use paid services. This field is read-only.
-    "billingAccountName": "A String", # The resource name of the billing account associated with the project, if
-        # any. For example, `billingAccounts/012345-567890-ABCDEF`.
+    "name": "A String", # The resource name for the `ProjectBillingInfo`; has the form
+        # `projects/{project_id}/billingInfo`. For example, the resource name for the
+        # billing information for project `tokyo-rain-123` would be
+        # `projects/tokyo-rain-123/billingInfo`. This field is read-only.
   }</pre>
 </div>
 
 <div class="method">
-    <code class="details" id="updateBillingInfo">updateBillingInfo(name, body, x__xgafv=None)</code>
+    <code class="details" id="updateBillingInfo">updateBillingInfo(name, body=None, x__xgafv=None)</code>
   <pre>Sets or updates the billing account associated with a project. You specify
 the new billing account by setting the `billing_account_name` in the
 `ProjectBillingInfo` resource to the resource name of a billing account.
@@ -153,9 +153,9 @@
 *open* billing account.
 
 Args:
-  name: string, The resource name of the project associated with the billing information
+  name: string, Required. The resource name of the project associated with the billing information
 that you want to update. For example, `projects/tokyo-rain-123`. (required)
-  body: object, The request body. (required)
+  body: object, The request body.
     The object takes the form of:
 
 { # Encapsulation of billing information for a GCP Console project. A project
@@ -164,16 +164,16 @@
   "projectId": "A String", # The ID of the project that this `ProjectBillingInfo` represents, such as
       # `tokyo-rain-123`. This is a convenience field so that you don't need to
       # parse the `name` field to obtain a project ID. This field is read-only.
-  "name": "A String", # The resource name for the `ProjectBillingInfo`; has the form
-      # `projects/{project_id}/billingInfo`. For example, the resource name for the
-      # billing information for project `tokyo-rain-123` would be
-      # `projects/tokyo-rain-123/billingInfo`. This field is read-only.
+  "billingAccountName": "A String", # The resource name of the billing account associated with the project, if
+      # any. For example, `billingAccounts/012345-567890-ABCDEF`.
   "billingEnabled": True or False, # True if the project is associated with an open billing account, to which
       # usage on the project is charged. False if the project is associated with a
       # closed billing account, or no billing account at all, and therefore cannot
       # use paid services. This field is read-only.
-  "billingAccountName": "A String", # The resource name of the billing account associated with the project, if
-      # any. For example, `billingAccounts/012345-567890-ABCDEF`.
+  "name": "A String", # The resource name for the `ProjectBillingInfo`; has the form
+      # `projects/{project_id}/billingInfo`. For example, the resource name for the
+      # billing information for project `tokyo-rain-123` would be
+      # `projects/tokyo-rain-123/billingInfo`. This field is read-only.
 }
 
   x__xgafv: string, V1 error format.
@@ -190,16 +190,16 @@
     "projectId": "A String", # The ID of the project that this `ProjectBillingInfo` represents, such as
         # `tokyo-rain-123`. This is a convenience field so that you don't need to
         # parse the `name` field to obtain a project ID. This field is read-only.
-    "name": "A String", # The resource name for the `ProjectBillingInfo`; has the form
-        # `projects/{project_id}/billingInfo`. For example, the resource name for the
-        # billing information for project `tokyo-rain-123` would be
-        # `projects/tokyo-rain-123/billingInfo`. This field is read-only.
+    "billingAccountName": "A String", # The resource name of the billing account associated with the project, if
+        # any. For example, `billingAccounts/012345-567890-ABCDEF`.
     "billingEnabled": True or False, # True if the project is associated with an open billing account, to which
         # usage on the project is charged. False if the project is associated with a
         # closed billing account, or no billing account at all, and therefore cannot
         # use paid services. This field is read-only.
-    "billingAccountName": "A String", # The resource name of the billing account associated with the project, if
-        # any. For example, `billingAccounts/012345-567890-ABCDEF`.
+    "name": "A String", # The resource name for the `ProjectBillingInfo`; has the form
+        # `projects/{project_id}/billingInfo`. For example, the resource name for the
+        # billing information for project `tokyo-rain-123` would be
+        # `projects/tokyo-rain-123/billingInfo`. This field is read-only.
   }</pre>
 </div>