Migrate to cargo_embargo. am: 16a2c62f18 am: c5641d58df am: c3545c3312

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/futures-test/+/2815987

Change-Id: I7e179e02a93e14b20393472e724281a9d0974416
Signed-off-by: Automerger Merge Worker <[email protected]>