Migrate to cargo_embargo. am: 99d47778c2 am: c4ee55ada0

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/unicode-width/+/2828074

Change-Id: I81bf4f1e974ed145cc2d385a83b13958ca387a3e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>