Removed unused imported namespaces in the file-upload example

Author: florello-tbox

core/file-upload.md

@@ -101,11 +101,8 @@ use App\Entity\MediaObject;
 use App\Form\MediaObjectType;
 use Sensio\Bundle\FrameworkExtraBundle\Configuration\IsGranted;
 use Symfony\Bridge\Doctrine\RegistryInterface;
-use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Component\Form\FormFactoryInterface;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpFoundation\Response;
-use Symfony\Component\Serializer\SerializerInterface;
 use Symfony\Component\Validator\Validator\ValidatorInterface;
 
 final class CreateMediaObjectAction