Add android_test_helper_app properties to java_defaults

Allows android_test_helper_apps to get their test_suites and
auto_gen_config properties from a java_defaults module.

Fixes: 179744452
Test: m checkbuild
Change-Id: Ifa09f9fd0a51d3a9682401e4c6bd2f82cd4f1b8a
diff --git a/java/java.go b/java/java.go
index bed232b..1b01f38 100644
--- a/java/java.go
+++ b/java/java.go
@@ -3318,6 +3318,7 @@
 		&android.ApexProperties{},
 		&RuntimeResourceOverlayProperties{},
 		&LintProperties{},
+		&appTestHelperAppProperties{},
 	)
 
 	android.InitDefaultsModule(module)