Merge "Support decoding gainmaps to alpha8 with BitmapFactory." into udc-dev am: ba62f46d64

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23121580

Change-Id: Ie0f60a6ba32920d2d98350e081527eb42018fe9d
Signed-off-by: Automerger Merge Worker <[email protected]>