Merge "Expand @FlaggedApi(Flags.FLAG) in *all* API signature files" into main am: 0c787f5b6e

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2765045

Change-Id: I588eaa0c680916c5274d25b960e83e911efcacce
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>