rust: Add common interface for binaries

Structs embedding binaryDecorator (rust_test, rust_benchmark, rust_fuzz)
are binaries as well, but won't pass checks against *binaryDecorator,
such as the check in StaticExecutable().

Add a binaryInterface that can be checked instead to simplify these
checks and ensure we catch all binaries.

Bug: 170672854
Test: rust_test, rust_benchmark return true StaticallyLinked
Change-Id: I2373d3663373a6977260785602a02d39a41320fe