Properly wire billing addresses to uncloud_service

uncloud_django_based/uncloud/uncloud_service/views.py

@@ -38,6 +38,12 @@ class MatrixServiceProductViewSet(ProductViewSet):
     def get_queryset(self):
         return MatrixServiceProduct.objects.filter(owner=self.request.user)
 
+    def get_serializer_class(self):
+        if self.action == 'create':
+            return OrderMatrixServiceProductSerializer
+        else:
+            return MatrixServiceProductSerializer
+
     @transaction.atomic
     def create(self, request):
         # Extract serializer data.