Merge branch 'stable-2.15' into stable-2.16

* stable-2.15:
  Set version to 2.15.12-SNAPSHOT
  Set version to 2.15.11
  Allow LFS-over-SSH created auth pass through ContainerAuthFilter
  Upgrade elasticsearch-rest-client to 6.6.1
  ElasticContainer: Bump the test server version to 5.6.15

Change-Id: I6a54f5b233cf9fa6053241b729cdd300f83dfdc9
tree: a526e7b8199bd46da6b2cd6df365c2e92ff4e634
  1. java/
  2. javatests/