Add AMBIENT_WALLPAPER to shell permissions

A wallpaper supporting ambient mode is required to check that WallpaperService#onAmbientModeChanged is called by the main thread.

Bug: 240112941
Test: atest CtsWallpaperTestcases
Change-Id: I6f7c36717366edd84802a58184798f72f2fea5cd
1 file changed