Merge branch 'stable-3.0' into stable-3.1

* stable-3.0:
  e2e Scenarios: Refine the gc checking resolution
  Prepare for new gerrit_api snapshot version usage
  Upgrade bazlets to latest stable-3.0
  Upgrade bazlets to latest stable-3.0
  CheckProjectStatisticsAfterGc: Make tests circular

Change-Id: I6a141f5a356c8ea8ffc08f656a7f39b3bab39bd7