docs:Add instructions on how to configure cross-project pubsub publisher

---
docs: document default disk type: pd-standard for non boot disk, pd-balanced for boot disk

---
docs: Update list of volume.mount_options field

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docs: Update GCS description of volume.mount_options field

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docs: Update links in the description of volume.mount_options field
PiperOrigin-RevId: 646637874

Source-Link: googleapis/googleapis@a0eb8ce

Source-Link: googleapis/googleapis-gen@ecfc6d5
Copy-Tag: eyJwIjoiYXBpcy9Hb29nbGUuQ2xvdWQuQmF0Y2guVjFBbHBoYS8uT3dsQm90LnlhbWwiLCJoIjoiZWNmYzZkNTgzZTdjYWQxMjkwYzQzNWVjODBkMzgxYjVlMzE2OTI4OCJ9

apis/Google.Cloud.Batch.V1Alpha/Google.Cloud.Batch.V1Alpha/Job.g.cs

@@ -2897,11 +2897,19 @@ public JobNotification Clone() {
     public const int PubsubTopicFieldNumber = 1;
     private string pubsubTopic_ = "";
     /// <summary>
-    /// The Pub/Sub topic where notifications like the job state changes
-    /// will be published. The topic must exist in the same project as
-    /// the job and billings will be charged to this project.
-    /// If not specified, no Pub/Sub messages will be sent.
-    /// Topic format: `projects/{project}/topics/{topic}`.
+    /// The Pub/Sub topic where notifications for the job, like state
+    /// changes, will be published. If undefined, no Pub/Sub notifications
+    /// are sent for this job.
+    ///
+    /// Specify the topic using the following format:
+    /// `projects/{project}/topics/{topic}`.
+    /// Notably, if you want to specify a Pub/Sub topic that is in a
+    /// different project than the job, your administrator must grant your
+    /// project's Batch service agent permission to publish to that topic.
+    ///
+    /// For more information about configuring Pub/Sub notifications for
+    /// a job, see
+    /// https://cloud.google.com/batch/docs/enable-notifications.
     /// </summary>
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)]
@@ -4419,7 +4427,9 @@ public void ClearSnapshot() {
         /// Disk type as shown in `gcloud compute disk-types list`.
         /// For example, local SSD uses type "local-ssd".
         /// Persistent disks and boot disks use "pd-balanced", "pd-extreme", "pd-ssd"
-        /// or "pd-standard".
+        /// or "pd-standard". If not specified, "pd-standard" will be used as the
+        /// default type for non-boot disks, "pd-balanced" will be used as the
+        /// default type for boot disks.
         /// </summary>
         [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
         [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)]

apis/Google.Cloud.Batch.V1Alpha/Google.Cloud.Batch.V1Alpha/Volume.g.cs

@@ -217,15 +217,19 @@ public string MountPath {
         = pb::FieldCodec.ForString(42);
     private readonly pbc::RepeatedField<string> mountOptions_ = new pbc::RepeatedField<string>();
     /// <summary>
-    /// For Google Cloud Storage (GCS), mount options are the options supported by
-    /// the gcsfuse tool (https://github.com/GoogleCloudPlatform/gcsfuse).
-    /// For existing persistent disks, mount options provided by the
-    /// mount command (https://man7.org/linux/man-pages/man8/mount.8.html) except
-    /// writing are supported. This is due to restrictions of multi-writer mode
-    /// (https://cloud.google.com/compute/docs/disks/sharing-disks-between-vms).
-    /// For other attached disks and Network File System (NFS), mount options are
-    /// these supported by the mount command
-    /// (https://man7.org/linux/man-pages/man8/mount.8.html).
+    /// Mount options vary based on the type of storage volume:
+    ///
+    /// * For a Cloud Storage bucket, all the mount options provided
+    /// by
+    ///   the [`gcsfuse` tool](https://cloud.google.com/storage/docs/gcsfuse-cli)
+    ///   are supported.
+    /// * For an existing persistent disk, all mount options provided by the
+    ///   [`mount` command](https://man7.org/linux/man-pages/man8/mount.8.html)
+    ///   except writing are supported. This is due to restrictions of
+    ///   [multi-writer
+    ///   mode](https://cloud.google.com/compute/docs/disks/sharing-disks-between-vms).
+    /// * For any other disk or a Network File System (NFS), all the
+    ///   mount options provided by the `mount` command are supported.
     /// </summary>
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     [global::System.CodeDom.Compiler.GeneratedCode("protoc", null)]