rust: Add dylib variants for bindgen modules.

Provide dylib variants for bindgen modules. This avoids issues where
bindgen modules being rlib-only results in a dependency tree
containing the same crate with two different linkages.

Bug: 294698705
Test: Example with binder and fmq crates builds.
Change-Id: Ia72f573db3c232c97276038e4315134d90033e10