Merge "update to v1.2.0" am: 6ea96a06ef am: 7bb22bfa35

Original change: https://android-review.googlesource.com/c/platform/external/webp/+/1566404

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I5e6ffc59e8f938df4e4cfca73a9811d4c1329ab4