Merge "external/webp: update to v1.1.0-28-g55a080e5" am: c4147d8f00 am: 663b190f19 am: 7d93739593 am: 539b9ec045

Original change: https://android-review.googlesource.com/c/platform/external/webp/+/1425968

Change-Id: Ia55ca0cdd2e3544328596b9515e9da659aab1b92