Merge branch 'stable-2.15' into stable-2.16

* stable-2.15:
  Upgrade bazlets to latest stable-2.15 to build with 2.15.10 API
  Automatically format BUILD file with buildifier lint mode
  Upgrade bazlets to latest stable-2.15 to build with 2.15.9 API
  Upgrade bazlets to latest stable-2.15 to build with 2.15.8 API
  Upgrade bazlets to latest stable-2.14 to build with 2.14.18 API
  Bazel: Include eclipse-out directory in .bazelignore

Change-Id: If0abb6191308f0a007c9a60d1588cc95ce3ece67