Merge branch 'stable-3.0'

* stable-3.0:
  Upgrade JGit to 5.3.6.201910020505-r
  Upgrade JGit to 5.1.12.201910011832-r
  Upgrade bazlets to latest stable-2.16

Change-Id: I7fc0941d5c4cd0b3008ec9a6b227b87a379306b4