Merge branch 'stable-2.16'

* stable-2.16:
  Upgrade bazlets to latest stable-2.16 to build with 2.16.6 API
  Add the standard LICENSE file
  Documentation: Fix the in-tree bazel test command
  Upgrade bazlets to latest stable-2.15 to build with 2.15.11 API

Change-Id: I4cca0f16e06d9590ea3de13a1ac3d17646ceb8cc