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

Merge "Changing flat request string to a set of element keys." into udc-dev am: 0d5caaf5 am: 93bcde85

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



Change-Id: I6b095047104342d0714e6682b289eb68e038bada
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>