Migrate to cargo_embargo. am: 95be593d39 am: 4c6b40707a

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/futures-macro/+/2824494

Change-Id: I4480b033de1c2fc2c622445af8b07ea7337d260a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>