Add preparer for overlay pre-singleton registration

It appears as though this is the first pre-singleton type to actually
be registered with the InitRegistrationContext as it failed due to an
uninitialized map, so this change also fixes that.

Bug: 182885307
Test: m nothing
Change-Id: Ibbf6d0db5f3c2fcc89291a16aa5f16b8b5009bd3
diff --git a/java/java_test.go b/java/java_test.go
index 913ed87..6bebf37 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -71,11 +71,11 @@
 	cc.PrepareForTestWithCcBuildComponents,
 	// Include all the default java modules.
 	PrepareForTestWithJavaDefaultModules,
+	PrepareForTestWithOverlayBuildComponents,
 	python.PrepareForTestWithPythonBuildComponents,
 	android.FixtureRegisterWithContext(func(ctx android.RegistrationContext) {
 		ctx.RegisterModuleType("java_plugin", PluginFactory)
 
-		ctx.RegisterPreSingletonType("overlay", OverlaySingletonFactory)
 		ctx.RegisterPreSingletonType("sdk_versions", sdkPreSingletonFactory)
 	}),
 	dexpreopt.PrepareForTestWithDexpreopt,