Clean up rust_test_host TEST_MAPPING after default update am: 9da11f0ba2 am: a2270c5afb

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/aho-corasick/+/1591060

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I16d92bf9235f730ff588ce55a3400078f4a661c9