Merge "Specify the wallpaper blast wrapper is a wallpaper window" into sc-dev...

Merge "Specify the wallpaper blast wrapper is a wallpaper window" into sc-dev am: 0954cfe6 am: 4c2d1417

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15132873

Change-Id: Iea6894b3637dfb65a6ed067f4ff77892d0c9ccc9