Refine oidc

What does this MR do?

This MR improves the current oidc use by

1. reusing the sample scripts of the oidc-module so that redundancies inherited from bap's scripts (including env, location, region and google-beta) are removed,
2. granting the permissions for the service account to create compute resources like vm's and firewalls so that the sast-ide-benchmark won't get 403 when using the oidc-module,
3. updating the doc.

What are the relevant issue numbers?

SAST IDE benchmark: OIDC/GCP bootstrap needs re... (gitlab-org/gitlab#477747 - closed) • Hua Yan • 17.4

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template
  • Job definition example
  • CI Templates
• Ensure the report version matches the equivalent schema version
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer