Merge "Fixes activity leak in Wallpaper Picker." into udc-dev am: b7c4aec8b0 am: ff91a0d5a4

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/23439007

Change-Id: I055860922d048f3abd151c755ef05425e875c108
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>