Clean up rust_test_host TEST_MAPPING after default update am: b1005cf632 am: f89968cee8 am: 6473e89458

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/libz-sys/+/1584585

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Idede0e17a784199f66502e1e976f65cd024cf989