* stable-2.14:
ElasticContainer: Allow to specify the docker container version to create
ElasticContainer: Include cause in AssumptionViolatedException
ElasticContainer: Create with static method
Acceptance tests: Replace embedded ES with docker testcontainer
Elasticsearch: replace native API in prod w/ REST
Changes to ReindexIT done in Iccf443102 ("Acceptance tests: Replace embedded
ES with docker testcontainer") are reverted in this merge since that test
currently doesn't work with Elasticsearch on stable-2.15 (issue 8799).
Change-Id: I21d8b10ebd450c7dc840846a5a0d836b4243dacc
d92ba3bc8d