Updates a survey in place; fields you omit keep their current values, and at least one field must be present. question_order renumbers the questions wholesale and must name exactly the survey's existing questions — the renumbering is applied one question at a time and is not transactional, so a failure midway can leave the order partly applied. Renaming the survey also renames and republishes its call routing; changing any other field leaves the routing alone. Keys the survey does not recognize are accepted and ignored.