Migrate to cargo_embargo. am: 25ae9e30f0 am: e4842cafbd am: 8ef599e7d6

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/fxhash/+/2822241

Change-Id: If2b7a31e1c49f68b7f73b2bf4edf0de2739afd19
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>