Returns the raw configuration object for an EntityDisplay entity.
The function returns the existing configuration entry if it exists, or creates a fresh structure.
string $entity_type: The entity type.
string $bundle: The bundle name.
string $view_mode: The view mode.
\Drupal\Core\Config\Config The configuration object.
function _update_8000_entity_get_display($entity_type, $bundle, $view_mode) {
  $id = $entity_type . '.' . $bundle . '.' . $view_mode;
  $config = config("entity.display.{$id}");
  if ($config
    ->get()) {
    return $config;
  }
  // Initialize a fresh structure.
  $uuid = new Uuid();
  $properties = array(
    'id' => $id,
    'uuid' => $uuid
      ->generate(),
    'targetEntityType' => $entity_type,
    'bundle' => $bundle,
    'mode' => $view_mode,
    'content' => array(),
  );
  foreach ($properties as $key => $value) {
    $config
      ->set($key, $value);
  }
  return $config;
}