Steps:

1. Modify version.properties to set patch=19, and commit the change for approval
2.  After merge, hit gerrit reply and send: stage-release
   1. smoke test the docker images
3. After release is staged, commit files to request push to repositories
   1. obtain the stage job's log path
   2. create releases/2.1.19.yaml and add in the stage job's log path
   3. commit change for approval