Migrate to cargo_embargo. am: daf8a2b219 am: 3ff463b920

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/async-trait/+/2799293

Change-Id: I398996ee64838463367bb05fd3a114291044700a
Signed-off-by: Automerger Merge Worker <[email protected]>