Summary:
This adds the same logic that we have in place with Litho for Yoga, allowing
unit tests to run with Gradle for Yoga. It'll still shell out to Buck to build
the native library, but that's hopefully only until we have found a way to reuse
the NDK build. For CI this shouldn't matter as we want to run `buck build`
anyway and the build step should be a no-op.
FB-Only:
This should unlock D5020044.
Reviewed By: emilsjolander
Differential Revision: D5104154
fbshipit-source-id: 48732fff6c1d100a155452f675de343aaf06427b