MQE-1427: Support _CREDS in <magentoCLI> action and in Data

- Adding missing return.

Author: ivy00johns

src/Magento/FunctionalTestingFramework/Module/MagentoWebDriver.php

@@ -643,15 +643,15 @@ public function fillSecretField($field, $value)
      * @param string $command
      * @param null   $arguments
      * @throws TestFrameworkException
-     * @return mixed
+     * @return string
      */
     public function magentoCLISecret($command, $arguments = null)
     {
         // to protect any secrets from being printed to console the values are executed only at the webdriver level as a
         // decrypted value
 
         $decryptedCommand = CredentialStore::getInstance()->decryptAllSecretsInString($command);
-        $this->magentoCLI($decryptedCommand, $arguments);
+        return $this->magentoCLI($decryptedCommand, $arguments);
     }
 
     /**