Migrate to cargo_embargo. am: 57a5148ddd am: f625e02646 am: cd98caf978

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/indexmap/+/2832458

Change-Id: I30ea7a1ef552e7acbe8387353b960de9e58b584d
Signed-off-by: Automerger Merge Worker <[email protected]>