Clean up rust_test_host TEST_MAPPING after default update am: 3d62e3b986 am: 3bffca16fb am: 684d177f4f

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

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ic5b8fbd374e8a96cda61c0e74f6ff31074381fe3