workbench instances: update documentation for instance_owners field (#12213) (#20161)

[upstream:8d44e7da8d5f3f1716d442407bf9a5e4bd2d62a4]

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/12213.txt

@@ -0,0 +1,3 @@
+```release-note: note
+workbench instances: update documentation for instance_owners field
+```

google/services/workbench/resource_workbench_instance.go

@@ -688,7 +688,9 @@ Format: {project_id}`,
 				ForceNew: true,
 				Description: `'Optional. Input only. The owner of this instance after creation. Format:
 '[email protected]' Currently supports one owner only. If not specified, all of
-the service account users of your VM instance''s service account can use the instance.'`,
+the service account users of your VM instance''s service account can use the instance.
+If specified, sets the access mode to 'Single user'. For more details, see
+https://cloud.google.com/vertex-ai/docs/workbench/instances/manage-access-jupyterlab'`,
 				Elem: &schema.Schema{
 					Type: schema.TypeString,
 				},

website/docs/r/workbench_instance.html.markdown

@@ -241,7 +241,9 @@ The following arguments are supported:
   (Optional)
   'Optional. Input only. The owner of this instance after creation. Format:
   `[email protected]` Currently supports one owner only. If not specified, all of
-  the service account users of your VM instance''s service account can use the instance.'
+  the service account users of your VM instance''s service account can use the instance.
+  If specified, sets the access mode to `Single user`. For more details, see
+  https://cloud.google.com/vertex-ai/docs/workbench/instances/manage-access-jupyterlab'
 
 * `disable_proxy_access` -
   (Optional)