Merge branch 'stable-3.0' into stable-3.1

* stable-3.0:
  Set Gerrit to 3.0.10
  Set Gerrit to 2.16.21
  Set Gerrit to 2.15.19
  Set Gerrit to 2.14.21
  Set version to 2.16.20

Change-Id: I6954ebd31942ba6d1b49d78b66c4d14a7a978007