Add defaults support to runtime_resource_overlay.

Bug: 154956723
Test: app_test.go
Change-Id: Ida29035ef45ec188c95a07a8bccaaa77eea486d7
diff --git a/java/java.go b/java/java.go
index 1c2e22a..5d77807 100644
--- a/java/java.go
+++ b/java/java.go
@@ -2745,6 +2745,7 @@
 		&sdkLibraryProperties{},
 		&DexImportProperties{},
 		&android.ApexProperties{},
+		&RuntimeResourceOverlayProperties{},
 	)
 
 	android.InitDefaultsModule(module)