Merge "Revert "Partially revert the usage of string enum."" into udc-qpr-dev...

Merge "Revert "Partially revert the usage of string enum."" into udc-qpr-dev am: f73d00ea am: 85084498

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24028952



Change-Id: I3cfb83d767e75ebce6e34b9c8623c262f638c032
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>