Move libgav1/* to * am: 8c0ea6aa4c

Original change: https://android-review.googlesource.com/c/platform/external/libgav1/+/1930857

Change-Id: I9f8f25f8ce863b4dcf7633c9a996dd5b09254351
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>