Remove the usage of private style attributes am: 8f68b26598

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/20334755

Change-Id: Iaad02fc37b3a996120cfc66d64539b2fc559dc74
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>