The alternative to "setReturnRawQueryResult" function, that returns array instead of QueryResultInterface is

$query->execute(TRUE);

Example

public function myFucntion() {

     $query = $this->createQuery();

     $query->getQuerySettings()->setReturnRawQueryResult(TRUE);

     return $query->execute();

}

Becomes

public function myFucntion() {

     $query = $this->createQuery();

     return $query->execute(TRUE);

}