This change accepts the `google.auth.credentials.Credentials` type for `BigQueryCredentialsConfig`, so any subclass of that, including `google.oauth2.credentials.Credentials` would work to integrate with BigQuery service. This opens up a whole range of possibilities, such as using service account credentials to deploy an agent using these tools.
PiperOrigin-RevId: 773190440
Right now the agent builder has to specify the bigquery scope explicitly for bigquery tools, which is somewhat unnecessary. With this change the user does not have to specify scopes, although they would still have the ability to overrides scopes if necessary.
PiperOrigin-RevId: 765354010
Google Team MemberandCopybara-Service
Xiang (Sean) ZhouandCopybara-Service