Merge "Move ImageWallpaper tasks to its own thread" into tm-qpr-dev am: 1467c855 am: 25ab8b37 am: 74c0c368 am: 9c2d468c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20982123



Change-Id: I9f073907bfc6a7a420aae01f6d59b2665e37fb74
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>