Merge "Revert "Add discrete contrast UI slider in the setting"" into udc-dev...

Merge "Revert "Add discrete contrast UI slider in the setting"" into udc-dev am: f9f6b80e am: b81af506

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Settings/+/21733631



Change-Id: I8062dfe5a83ddfc9abe47706a21449553eb6a71c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>