Migrate to cargo_embargo. am: 34065597a2 am: 4f574e8cdf

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/rustc-demangle-capi/+/2832426

Change-Id: I5c93133b8663f1bef76836a53e24384903284fc0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>