docs: docs update (#911)

Thank you for opening a Pull Request! Before submitting your PR, there are a few things you can do to make sure it goes smoothly:
- [ ] Make sure to open an issue as a [bug/issue](https://github.com/googleapis/google-api-python-client/issues/new/choose) before writing your code!  That way we can discuss the change, evaluate designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)

Fixes #<issue_number_goes_here> 🦕
diff --git a/docs/dyn/pubsub_v1.projects.topics.snapshots.html b/docs/dyn/pubsub_v1.projects.topics.snapshots.html
index 694a985..dc5b0bf 100644
--- a/docs/dyn/pubsub_v1.projects.topics.snapshots.html
+++ b/docs/dyn/pubsub_v1.projects.topics.snapshots.html
@@ -75,16 +75,16 @@
 <h1><a href="pubsub_v1.html">Cloud Pub/Sub API</a> . <a href="pubsub_v1.projects.html">projects</a> . <a href="pubsub_v1.projects.topics.html">topics</a> . <a href="pubsub_v1.projects.topics.snapshots.html">snapshots</a></h1>
 <h2>Instance Methods</h2>
 <p class="toc_element">
-  <code><a href="#list">list(topic, pageSize=None, pageToken=None, x__xgafv=None)</a></code></p>
+  <code><a href="#list">list(topic, pageToken=None, pageSize=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Lists the names of the snapshots on this topic. Snapshots are used in</p>
 <p class="toc_element">
   <code><a href="#list_next">list_next(previous_request, previous_response)</a></code></p>
 <p class="firstline">Retrieves the next page of results.</p>
 <h3>Method Details</h3>
 <div class="method">
-    <code class="details" id="list">list(topic, pageSize=None, pageToken=None, x__xgafv=None)</code>
+    <code class="details" id="list">list(topic, pageToken=None, pageSize=None, x__xgafv=None)</code>
   <pre>Lists the names of the snapshots on this topic. Snapshots are used in
-&lt;a href="https://cloud.google.com/pubsub/docs/replay-overview"&gt;Seek&lt;/a&gt;
+&lt;a href=&quot;https://cloud.google.com/pubsub/docs/replay-overview&quot;&gt;Seek&lt;/a&gt;
 operations, which allow
 you to manage message acknowledgments in bulk. That is, you can set the
 acknowledgment state of messages in an existing subscription to the state
@@ -93,10 +93,10 @@
 Args:
   topic: string, Required. The name of the topic that snapshots are attached to.
 Format is `projects/{project}/topics/{topic}`. (required)
-  pageSize: integer, Maximum number of snapshot names to return.
   pageToken: string, The value returned by the last `ListTopicSnapshotsResponse`; indicates
 that this is a continuation of a prior `ListTopicSnapshots` call, and
 that the system should return the next page of data.
+  pageSize: integer, Maximum number of snapshot names to return.
   x__xgafv: string, V1 error format.
     Allowed values
       1 - v1 error format
@@ -106,11 +106,11 @@
   An object of the form:
 
     { # Response for the `ListTopicSnapshots` method.
-    "nextPageToken": "A String", # If not empty, indicates that there may be more snapshots that match
+    &quot;nextPageToken&quot;: &quot;A String&quot;, # If not empty, indicates that there may be more snapshots that match
         # the request; this value should be passed in a new
         # `ListTopicSnapshotsRequest` to get more snapshots.
-    "snapshots": [ # The names of the snapshots that match the request.
-      "A String",
+    &quot;snapshots&quot;: [ # The names of the snapshots that match the request.
+      &quot;A String&quot;,
     ],
   }</pre>
 </div>
@@ -124,7 +124,7 @@
   previous_response: The response from the request for the previous page. (required)
 
 Returns:
-  A request object that you can call 'execute()' on to request the next
+  A request object that you can call &#x27;execute()&#x27; on to request the next
   page. Returns None if there are no more items in the collection.
     </pre>
 </div>