createQueryBuilder return a well-formatted JSON

Good, I have an action in my controller that what it does is collect the records of the entity Address and make a Join with the City entity to obtain the name of the city (City entity field name), for this I have this code that works but I returned the json in this format in two levels, I would like to receive all the information at the same level

/**
 * @param Request $request
 * @Route("/find/", name="admin_Address_find")
 * @return JsonResponse
 */
public function findShopAction(Request $request)
{
    $em = $this->getDoctrine()->getManager();
    $qb = $em->createQueryBuilder();
    $ap = $qb->select('a','c.name as nameCity')
        ->from('AppBundle\Entity\Address', 'a')
        ->innerJoin('AppBundle\Entity\City','c','WITH','a.city = c.id')
        ->getQuery()
        ->getArrayResult();
    return new JsonResponse($ap);
}

The resulting code of the JSOn is this

[{"0": {"id": 3, "addressName": "9", "numberAddress": "9", "phone": 9, "nameCity": "BCN"}, {"0": {"id": 4, "addressName": "4", "numberAddress": "4", "phone": null, "nameCity": "BCN"}, {"0": {"id": 34, "addressName": "address 2", "numberAddress": "47", "phone": 973112233, "nameCity": "BCN"}, {"0": {"id": 35, "addressName": "address", "numberAddress": "1", "phone": 1, "nameCity": "BCN"}]