Migrate to cargo_embargo. am: bacccafd8f am: dcfcb04968

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/futures-io/+/2826413

Change-Id: I7deb3eac1d71b2c40662154c969a68e5797ca747
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>