Migrate to cargo_embargo. am: c0fe728e9d am: 07fc0e6e58 am: c882948907

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/data-encoding/+/2824673

Change-Id: Ibce05ffb170c8d8c710b47bdbaf64d051687f959
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>