Clean up rust_test_host TEST_MAPPING after default update am: 3d62e3b986 am: 3bffca16fb

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/tinyvec_macros/+/1584444

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Id74a0f124316bca3cad5f71799c2c0760c03442a