Add rust_test and update TEST_MAPPING am: 25207b9171 am: e47269984a am: 9cd6feda6d am: 3b682d4e7a

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

Change-Id: I0152e9b67835dbff31272b40da4c763046c7ab58