Migrate to cargo_embargo. am: 8b829742b4 am: d1570a182a am: 9c5def094d

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/form_urlencoded/+/2822399

Change-Id: If36d5ab9f45332e4c5617fa91efe4a85d6dacc46
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>