Merge branch 'stable-2.16' into stable-3.0

* stable-2.16:
  Upgrade bazlets to latest stable-2.16 to build with 2.16.11.1 API
  Upgrade bazlets to latest stable-2.15 to build with 2.15.16 API
  Upgrade bazlets to latest stable-2.15 to build with 2.15.15 API

Change-Id: Ie74d2a086e641798cc972f5c40d1609e75868bbd