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

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

Change-Id: I3e4033d6ea20248cdf8dcf3798eb7aa02f4bfc4a