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: I6c5a8c59d2195a3b177c0a4fbbbe6a285c5885ce