Allow generation of resource provider for library modules

Currently, an Application object is required to generate the ResourceProvider. It also seems that the current library generation from the gradle plugin does not generate the R class (or at least it does not get included in the annotation processor's environment).

As a result, even if you include a dummy Application object with the @RpApplication annotation, you will still get an empty resource provider, because it will not find the R class to read the resources from.

We should check to see if there's a workaround to this or not.