[automerger skipped] Merge "Only allow trusted overlays to specify FLAG_SLIPPERY" into sc-dev am: 94fb6eff am: 34798dca -s ours

am skip reason: Merged-In Ia30f1c38d5ddb351c90b748ea76448a76a9dde7b with SHA-1 0657e199 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15748730

Change-Id: I5d2567606884c3d988d37443886378760d2122f4