Add an exported flag in manifest am: 6fdf12a56f am: 4292a37c4b am: a040f43f1f am: 04a6483428 am: ba030bbc9b

Original change: https://android-review.googlesource.com/c/platform/packages/apps/WallpaperPicker/+/1266645

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I48e263eb7f085dfd86ffb16cd23731f1f4682016