Migrate to cargo_embargo. am: f13a18b8e7 am: 7fd07ea45f am: 7da60cb167

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/libloading/+/2838079

Change-Id: Iab2cf125c7a086b81decce757ebdf3687b2c9eaf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>