Migrate to cargo_embargo. am: 95be593d39 am: 1fce789904 am: c0dffccee6

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

Change-Id: I862612a5afaa7606ccae49dab87e572cd9366e23
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>