libbinder_rs: Build libbinder_ndk_sys on Trusty

Adds a rules.mk build file to build the C wrapper
crate on Trusty with bindgen.

Bug: 242243245
Test: build binder_ndk_sys as a dependency of skel_rust
Change-Id: I54af010a49763bda785230261d56485ffd15e98f
2 files changed