Merge "Only generate paint/mask bitmap when starting animations" into sc-dev...

Merge "Only generate paint/mask bitmap when starting animations" into sc-dev am: 7df767f3 am: e0ad3c6f

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14390053

Change-Id: Ie6e582c24303a630e545dc7b9a1d36f75f9333c3