Merge branch 'stable-2.16'

* stable-2.16:
  Upgrade bazlets to latest stable-2.16 to build with 2.16.6 API
  LfsApiServlet: Restore good permission backend check for project access
  Add the standard LICENSE file
  Upgrade bazlets to latest stable-2.15 to build with 2.15.11 API
  LfsApiServlet: use LfsRequest.is(Upload|Download) methods

Change-Id: If93b9af052c23c9b8d4e5512532521100a0f3320