am 50768991: (-s ours) am 6970ca0c: am 55c46211: am fa26ce84: am a19e1e2c: Update build tools version to 21.1.2. DO NOT MERGE.

* commit '507689911637f3935d8a584f766d77312da0e40f':
  Update build tools version to 21.1.2. DO NOT MERGE.