ACP2E-2990: Customer "created_at" date Not Converted to store time zone upon export

 - Fixed the CR comments.

Author: devarul

app/code/Magento/CustomerImportExport/Model/Export/Customer.php

@@ -160,11 +160,14 @@ public function exportItem($item)
         $row = $this->_addAttributeValuesToRow($item);
         $row[self::COLUMN_WEBSITE] = $this->_websiteIdToCode[$item->getWebsiteId()];
         $row[self::COLUMN_STORE] = $this->_storeIdToCode[$item->getStoreId()];
-        $row[self::COLUMN_CREATED_AT] = $this->_localeDate->formatDate(
-            $item->getCreatedAt(),
-            \IntlDateFormatter::MEDIUM,
-            true
-        );
+        if (isset($row[self::COLUMN_CREATED_AT])) {
+            $row[self::COLUMN_CREATED_AT] = $this->_localeDate->formatDate(
+                $item->getCreatedAt(),
+                \IntlDateFormatter::MEDIUM,
+                true
+            );
+            $row[self::COLUMN_CREATED_AT] = (new \DateTime($row[self::COLUMN_CREATED_AT]))->format('Y-m-d H:i:s');
+        }
 
         $this->getWriter()->writeRow($row);
     }

dev/tests/integration/testsuite/Magento/CustomerImportExport/Model/Export/CustomerTest.php

@@ -166,6 +166,7 @@ private function checkExportData(array $lines, array $expectedAttributes): void
                 \IntlDateFormatter::MEDIUM,
                 true
             );
+            $data['created_at'] = (new \DateTime($data['created_at']))->format('Y-m-d H:i:s');
             $exportData = $lines['data'][$data['email']];
             $exportData = $this->unsetDuplicateData($exportData);