Migrate to cargo_embargo. am: 8db550a9e9 am: 2dc01c2028

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/threadpool/+/2828054

Change-Id: I962a409a90a7270e5bc7beb34c69d2be8fa4d73a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>