Migrate to cargo_embargo. am: 3e1c42f469 am: 8f5a27a241

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/fnv/+/2796414

Change-Id: I3413452fe16b4cfdbf4f80df26b4cc093934fd7d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>