MAGETWO-87496: Switch updatecart qty input validators to dynamic instead of hardcoding #13462

 - Merge Pull Request #13462 from gil--/magento2:feature/dynamic-validation-updateform
 - Merged commits:
   1. 1ad527a

Author: rogyar

app/code/Magento/Checkout/view/frontend/templates/cart/item/configure/updatecart.phtml

@@ -23,7 +23,7 @@
                            value=""
                            title="<?= /* @escapeNotVerified */ __('Qty') ?>"
                            class="input-text qty"
-                           data-validate="{'required-number':true,digits:true}"/>
+                           data-validate="<?= $block->escapeHtml(json_encode($block->getQuantityValidators())) ?>"/>
                 </div>
             </div>
             <?php endif; ?>