Merge branch 'stable-3.0' into stable-3.1

* stable-3.0:
  Bump Bazel version to 3.7.0
  Upgrade bazlets to latest stable-3.0 to build with 3.0.13 API

Change-Id: I647e8fa47d9e6a4f33d1de72ae1a4fc457b4dcd4