Migrate to cargo_embargo. am: 890d762137

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/linkme-impl/+/2822777

Change-Id: I9156f050f4eab95e7152fab20b0a1c362920cbb4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>