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.go b/java/java.go
index 47dd957..b9c06a8 100644
--- a/java/java.go
+++ b/java/java.go
@@ -340,6 +340,9 @@
 	// list of additional targets for checkbuild
 	additionalCheckedModules android.Paths
 
+	// Extra files generated by the module type to be added as java resources.
+	extraResources android.Paths
+
 	hiddenAPI
 	dexpreopter
 }
@@ -1113,6 +1116,7 @@
 	dirArgs, dirDeps := ResourceDirsToJarArgs(ctx, j.properties.Java_resource_dirs,
 		j.properties.Exclude_java_resource_dirs, j.properties.Exclude_java_resources)
 	fileArgs, fileDeps := ResourceFilesToJarArgs(ctx, j.properties.Java_resources, j.properties.Exclude_java_resources)
+	extraArgs, extraDeps := resourcePathsToJarArgs(j.extraResources), j.extraResources
 
 	var resArgs []string
 	var resDeps android.Paths
@@ -1123,6 +1127,9 @@
 	resArgs = append(resArgs, fileArgs...)
 	resDeps = append(resDeps, fileDeps...)
 
+	resArgs = append(resArgs, extraArgs...)
+	resDeps = append(resDeps, extraDeps...)
+
 	if Bool(j.properties.Include_srcs) {
 		srcArgs, srcDeps := SourceFilesToJarArgs(ctx, j.properties.Srcs, j.properties.Exclude_srcs)
 		resArgs = append(resArgs, srcArgs...)