Merge branch 'stable-2.16' into stable-3.0

* stable-2.16:
  ElasticContainer: Upgrade V6_8 to elasticsearch 6.8.9
  ElasticVersion: Replace unchecked throw w/ javadoc
  Remove obsolete parts from Java code style guide
  Elasticsearch: Remove support for EOL 6.5 version

Change-Id: Iab0ccdf102d510f001400c1ed140edc6014f2536
tree: d780083a6147a91041ba778a65fa82bb43681373
  1. java/
  2. javatests/