Clean up rust_test_host TEST_MAPPING after default update am: b1005cf632 am: f89968cee8 am: 6473e89458 am: 8582a8fba9

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

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ibbef447e59a47369feb0a3228c565f1107258743