MC-42249: No form validation for negative quantity on bundle products

- Added to allow the validation functionality for php 7.4 version.

Author: devarul

app/code/Magento/Bundle/ViewModel/ValidateQuantity.php

@@ -19,12 +19,12 @@ class ValidateQuantity implements ArgumentInterface
     /**
      * @var Json
      */
-    private Json $serializer;
+    private $serializer;
 
     /**
      * @var ProductView
      */
-    private ProductView $productView;
+    private $productView;
 
     /**
      * @param Json $serializer