Merge branch 'stable-2.15' into stable-2.16

* stable-2.15:
  Add the standard LICENSE file
  Documentation: Fix the in-tree bazel test command
  Start dockerized postgres server in junit test using testcontainers
  PostgresQueueTest#testList: Tolerate up to 1s skew in queued time stamp

Change-Id: I14b496401a796846c0db3505dae0d81a5e473eda