[automerger skipped] Add android:exported tag am: c61b39439e am: f7e402b885 am: 4ffb4eee52 -s ours

am skip reason: Merged-In Icf7492e392cf20986990be2752e6357d4cdb352c with SHA-1 9a342bde5e is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/developers/samples/android/+/15600751

Change-Id: I5fe81eeb77b37e2903cc357ad77c1d9b1b02818c