Merge "Update wallpaper offset when changing target from null" into sc-dev am: ccdb324274 am: 2e6888a1e0

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15521640

Change-Id: Ic6e96c94203ac2fa856facbea7531a1f6ce66cd7