Expose setFullScreenActions for extending class am: 39ec8a0abb am: d4bb2c3790 am: 7a59984190

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/WallpaperPicker2/+/15100478

Change-Id: I5e14e561c73f5bcde96116cb5340e6cea996f3d1