Revise layout of LivePreviewFragment am: 25d3a24056 am: 18946c6f61

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/WallpaperPicker2/+/11367458

Change-Id: I6da963a9780c8eeca5deb3134bfc698adcdb0a8b