Android S Preview 1
Clean up rust_test_host TEST_MAPPING after default update

After b/177689340, rust_test_host doesn't need TEST_MAPPING config anymore to run in
presubmit.

Change-Id: I30d7d66ab1e291f0abbf5b7211df5cf5690d5f96
Test: presubmit
Bug: 178646865
1 file changed