Migrate to cargo_embargo. am: e8e520b2d4 am: 4eb2b5bd0d am: a9f8bc05e8

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/rustversion/+/2828052

Change-Id: I25a111ff61bcbd84e4ea26d78dd190551e0f7f93
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>