Clean up rust_test_host TEST_MAPPING after default update am: 28312b56b0 am: 963de5e48d

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/pin-utils/+/1584348

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ie9ec20879c82106958f49dc481f1d7b2f0de7bcd