Merge branch 'stable-3.0' into stable-3.1

* stable-3.0:
  Update git submodules
  ElasticV6QueryChangesTest: Close indices after test
  Update git submodules
  Add support for Elasticsearch version 7.5.*

Change-Id: I7469369ac5ea53ac1716ef9a5e433a91ad9b25af
tree: fb036f9c45b0330a562d8572879201152978d425
  1. java/
  2. javatests/