Merge branch 'stable-3.1' into stable-3.2

* stable-3.1:
  Upgrade bazlets to latest stable-3.1 to build with 3.1.8 API
  Upgrade bazlets to latest stable-3.0 to build with 3.0.12 API
  Upgrade bazlets to latest stable-2.16 to build with 2.16.22 API

Change-Id: If1eee72e12c98aef8047c62e68750a57ad3278b6