GeneralSettingsForm constructor.
\Drupal\paragraphs\ParagraphsBehaviorManager $paragraphs_behavior_manager: The paragraphs type feature manager service.
\Drupal\Core\Messenger\MessengerInterface $messenger: The messenger service.
public function __construct(ParagraphsBehaviorManager $paragraphs_behavior_manager, MessengerInterface $messenger) {
$this->paragraphsBehaviorManager = $paragraphs_behavior_manager;
$this->messenger = $messenger;
}