Clean up rust_test_host TEST_MAPPING after default update am: b8bba2380d am: f7add38751 am: 600080cdec

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/bitflags/+/1582230

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ibaa89d58028f2aadb92039b5268c9d0aeccd7287