Merge "Support decoding gainmaps to alpha8 with BitmapFactory." into udc-dev am: ba62f46d

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



Change-Id: I6bd7fefbcf6a1e71f9706d0572c872954175c019
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>