Merge branch 'stable-3.0'

* stable-3.0:
  Upgrade bazlets to latest stable-2.15 to build with 2.15.15 API
  Upgrade testcontainers to 1.12.0
  Upgrade bazlets to latest stable-3.0

Change-Id: Ib42e59e8613df1f406c79f58eb9132392e211236