Merge branch 'stable-3.4'

* stable-3.4:
  Elasticsearch: Discontinue EOL version 7.4 support

Change-Id: Iff6820b9280950e3f756ed3dab209a260fd58e0e
tree: 3c9480b1d5489282619b9641c7e246f25219620f
  1. java/
  2. javatests/