Migrate to cargo_embargo. am: 25ae9e30f0 am: e4842cafbd

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

Change-Id: I204eaf5959885d1206af9736c0d51affd465ddc9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>