Merge "Merge "Update wallpaper offset when changing target from null" into sc-dev am: ccdb3242 am: a1d274c9" into sc-qpr1-dev-plus-aosp am: 89d78c25

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

Change-Id: I9438190b3c8754de462713423310ec010994e039