Migrate to cargo_embargo. am: c0fe728e9d am: c553af622d am: 71bf1640d7

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

Change-Id: I8a6723162f2e60f2c9bfabbb063b9b7a65663a49
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>