Merge "Changing flat request string to a set of element keys." into udc-dev am: 0d5caaf550

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22189064

Change-Id: I46eb63f5c4d1afc7ccd47067adb59cccb2ec9cca
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>