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

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



Change-Id: Ia87b8d3163e29c35fea3c49722d1d22ccb40c11d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>