Migrate to cargo_embargo. am: d4cc133005 am: 5503b46dec am: 880742b9ee

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/proc-macro-error-attr/+/2830450

Change-Id: I0960d337defaaeb4a14a2655105498d1137a15b1
Signed-off-by: Automerger Merge Worker <[email protected]>