Merge "Expand @FlaggedApi(FLAG) constants in API signature files" into main am: 779ebfb62b am: 0275f893c2

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2759286

Change-Id: I29b4d2cf845030d88f030c5b6a16160367ed5888
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>