Add rust_test and update TEST_MAPPING am: 2073710dde am: 5eb6104876 am: 276a00db19 am: f8cfaabca0 am: 0d607e9702

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/rustc-hash/+/1365658

Change-Id: I64c7d6bd8dbcfd083549beb9035d886738865364