Allow module types to generate resources

Robolectric will need to generate extra resources to be added to
the jar.

Test: TestResources
Change-Id: I028f91ea8fc5d1e59e4e805876d70f57d8899f11
diff --git a/java/java_resources.go b/java/java_resources.go
index 7161168..1bbeb9a 100644
--- a/java/java_resources.go
+++ b/java/java_resources.go
@@ -98,6 +98,14 @@
 
 	files := android.PathsForModuleSrcExcludes(ctx, res, exclude)
 
+	args = resourcePathsToJarArgs(files)
+
+	return args, files
+}
+
+func resourcePathsToJarArgs(files android.Paths) []string {
+	var args []string
+
 	lastDir := ""
 	for i, f := range files {
 		rel := f.Rel()
@@ -113,5 +121,5 @@
 		lastDir = dir
 	}
 
-	return args, files
+	return args
 }