Merge branch 'stable-2.15' into stable-2.16

* stable-2.15:
  Add standalone bazel build for 2.14.17 with Eclipse project generation
  Remove leftovers from Buck-based build
  Format Java files with google-java-format
  Format BUILD file with buildifier

Also update the bazlets revision in WORKSPACE to build with 2.16.

Change-Id: I2284cbec082b3f1fa322730504755ac8bfbd7a0b