Migrate to cargo_embargo. am: d939d4fef1 am: 7010d0dfda am: 51c4cdd5ff

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/rand_core/+/2824510

Change-Id: Ic580d54ce922b4af5ac9bd053d9cdc2e0a0d3c45
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>