Add preparers for python

Bug: 181070625
Test: m nothing
Change-Id: I590ad62db6fd62719c83286780563cf6d55e3e17
diff --git a/python/library.go b/python/library.go
index b724d2b..9663b3c 100644
--- a/python/library.go
+++ b/python/library.go
@@ -21,8 +21,12 @@
 )
 
 func init() {
-	android.RegisterModuleType("python_library_host", PythonLibraryHostFactory)
-	android.RegisterModuleType("python_library", PythonLibraryFactory)
+	registerPythonLibraryComponents(android.InitRegistrationContext)
+}
+
+func registerPythonLibraryComponents(ctx android.RegistrationContext) {
+	ctx.RegisterModuleType("python_library_host", PythonLibraryHostFactory)
+	ctx.RegisterModuleType("python_library", PythonLibraryFactory)
 }
 
 func PythonLibraryHostFactory() android.Module {