Migrate to cargo_embargo. am: f13a18b8e7

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

Change-Id: I90649f1bb0c0f47d0c1c568e6ff6ee3a1d375e43
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>