Migrate to cargo_embargo. am: 2b68c7ca5a am: 279eca3c46 am: c6dc74b02f

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/cesu8/+/2822395

Change-Id: Ibb06d146538b73045a660f0070b90a8c58c7a131
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>