Migrate to cargo_embargo. am: 3742ab94f0 am: eab417ce75

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/which/+/2822243

Change-Id: Icbf240fc80040b15ae04afe9828121bb484b2e9a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>