Merge branch 'stable-2.16'

* stable-2.16:
  Upgrade bazlets to latest stable-2.16
  Upgrade bazlets to latest stable-2.15
  Upgrade bazlets to latest stable-2.14
  Update bazlets to fix build with bazel 0.23
  Update bazlets to fix build with bazel 0.23
  Upgrade bazlets to latest stable-2.16 to build with 2.16.6 API
  Upgrade bazlets to latest stable-2.15 to build with 2.15.11 API
  Fix preference retrieval

Change-Id: I045e2152fc38ffa8eafb05c20a626b1985bbe114