ElasticContainer: Use Elasticsearch 6.4.1 for V6_4 tests

Change-Id: I9dec94b81079574da0c66bca2860e093f70be8f4
1 file changed
tree: d16fab1a65724428e66dbc0b2b5ebeec256609d8
  1. gerrit-acceptance-tests/
  2. gerrit-elasticsearch/
  3. gerrit-pgm/