added created_at and updated_at column in quality validation model

app/Models/QualityValidation.php

@@ -35,6 +35,8 @@ class QualityValidation extends Model
         'part_validation5',
         'operator_id',
         'uom',
+        'created_at',
+        'updated_at',
         'serial_number',
         'sap_msg_status',
         'sap_msg_description',