magento#1029 Add string postcode and comment

Author: osrecio

app/code/Magento/CustomerGraphQl/Model/Customer/Address/CreateCustomerAddress.php

@@ -110,10 +110,11 @@ public function validateData(array $addressData): void
         $attributes = $this->getAllowedAddressAttributes->execute();
         $errorInput = [];
 
+        //Add error for empty postcode with country with no optional ZIP
         if (!in_array($addressData['country_id'], $this->directoryData->getCountriesWithOptionalZip())
             && (!isset($addressData['postcode']) || empty($addressData['postcode']))
         ) {
-            $errorInput[] = $addressData['postcode'];
+            $errorInput[] = 'postcode';
         }
 
         foreach ($attributes as $attributeName => $attributeInfo) {