Revert^2 "rust: Use autogenerated Trusty makefile rules" am: ac9e6f78ed

Original change: https://android-review.googlesource.com/c/trusty/app/keymint/+/2746780

Change-Id: I919f89b19f0a4358e222b4b5dd951274ce09b630
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>