Add rust_test and update TEST_MAPPING am: 25207b9171 am: e47269984a am: 9cd6feda6d

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/shlex/+/1365397

Change-Id: Ie3edea7a07b0dc9c8d24df50fd1d9955f8408261