Changes to Speech to Text

removed the media type application/json from the request body

added the new optional header request parameter model

added the media type multipart/form-data to the request body

added the non-success response with the status 503

removed the non-success response with the status 422

added the optional property language to the response with the 200 status

added the optional property language_code to the response with the 200 status

added the optional property reason to the response with the 401 status

added the optional property reason to the response with the 402 status