Merge branch 'stable-2.16' into stable-3.0

* stable-2.16:
  Add support for Elasticsearch version 7.5.*

Change-Id: Ie416a7e6ad8752b092253c54c1d37617bec038f2
tree: 7ea0ece7b6042f51a4491045da3355e35bdb1cb2
  1. java/
  2. javatests/