NIU Actions: Change AppTheme to LauncherTheme am: d317f17273 am: aa10ba9d0b am: b716f13461

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15413718

Change-Id: I5d5fd0759aecc1969c2ed570463b36c304afb9ec