Add Trusty rules.mk file am: 7513c72639 am: c46bcebcdf

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/async-trait/+/2770391

Change-Id: I009a16d30408e7c4a4bdea5d62ab41b4ca34072e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>