Call hook in java_sdk_library after droidstubs generation

Currently, droidstubs module create java_api_contribution module, but
when a java_sdk_library module dynamically creates a droidstubs module,
java_api_contribution is not created as the hook inside droidstubs get
lost. Therefore, call hook inside sdk_library after creating the
droidstubs module.

Test: m
Change-Id: I68bf1d796f6f9a6f81011ae35e4991b6ed1421ea
diff --git a/java/sdk_library_test.go b/java/sdk_library_test.go
index 210bfc3..1d0c13d 100644
--- a/java/sdk_library_test.go
+++ b/java/sdk_library_test.go
@@ -120,6 +120,7 @@
 	result.ModuleForTests(apiScopePublic.stubsSourceModuleName("foo"), "android_common")
 	result.ModuleForTests(apiScopeSystem.stubsSourceModuleName("foo"), "android_common")
 	result.ModuleForTests(apiScopeTest.stubsSourceModuleName("foo"), "android_common")
+	result.ModuleForTests(apiScopePublic.stubsSourceModuleName("foo")+".api.contribution", "")
 	result.ModuleForTests("foo"+sdkXmlFileSuffix, "android_common")
 	result.ModuleForTests("foo.api.public.28", "")
 	result.ModuleForTests("foo.api.system.28", "")