Inject \Drupal::entityQuery to Controller

Before:

$moderators = \Drupal::entityQuery('user')
 ->condition('status', 1)
 ->condition('roles', $moderator_role)
 ->execute();

After:

$query = $this->entityTypeManager()->getStorage('user')->getQuery();
$query->condition('status', 1)
 ->condition('roles', $moderator_role);
$moderators = $query->execute();