Support WCG wallpaper preview in WallpaperPicker am: 1bb1f51612 am: 0a40aaef5b am: 32a102e1fa

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/WallpaperPicker2/+/11546238

Change-Id: Ibea88d9e9c7fc285dee6ad4cd71929f3fb91b83b