* stable-3.2: Update git submodules Fix documentation of `container.slave` Fix documentation of `container.slave` Update git submodules Update git submodules Submit: Use updated change for response Remove Content-Type header from 'Submit Revision' example Update git submodules Add support for Elasticsearch version 7.8.* Fix `parent` in `gr-change-metadata` when there is no revision Change-Id: Ifaaad90a7343da4e301137616bc7c82e92bd6f3c