Update es-connectors-gmail.md (elastic#135591)

In addition to the directory user read-only scope, ES needs the Group Directory read only as well as the gmail readonly.

Author: CyberneticNomad-v808

docs/reference/search-connectors/es-connectors-gmail.md

@@ -132,6 +132,8 @@ To get started, log into [Google Cloud Platform](https://cloud.google.com) and g
     You need to grant the following **OAuth Scopes** to your service account:
 
     * `https://www.googleapis.com/auth/admin.directory.user.readonly`
+    * `https://www.googleapis.com/auth/admin.directory.group.readonly`
+    * `https://www.googleapis.com/auth/gmail.readonly`
 
     This step allows the connector to access user data and their group memberships in your Google Workspace organization.
 
@@ -296,4 +298,4 @@ See [Security](/reference/search-connectors/es-connectors-security.md).
 
 This connector is built in Python with the [Elastic connector framework](https://github.com/elastic/connectors/tree/main).
 
-View the [source code for this connector](https://github.com/elastic/connectors/tree/main/connectors/sources/gmail.py) (branch *main*, compatible with Elastic *9.0*).
+View the [source code for this connector](https://github.com/elastic/connectors/tree/main/connectors/sources/gmail.py) (branch *main*, compatible with Elastic *9.0*).