Unable to perform update when adding new menu field
Just update entities it will work: run the command drush entity-updates.
No need for hook_update_N.
You can add hook_install to update entities automatically when you install your module don't need to do it by command each time or get the error on every installation .  



/**
 * Implements hook_install().
 */
function my_module_install() {
  \Drupal::service('entity.definition_update_manager')->applyUpdates();
}