Como ajustar o ContentType e charset no datasnap restful

gistfile1.txt

procedure TWebModule1.WebModuleBeforeDispatch(Sender: TObject;
  Request: TWebRequest; Response: TWebResponse; var Handled: Boolean);
begin
  Response.ContentType := 'text/html; charset=utf-8'; 
  Response.ContentEncoding := 'utf-8'; 
  
  if FServerFunctionInvokerAction <> nil then
    FServerFunctionInvokerAction.Enabled := AllowServerFunctionInvoker;
end;

//NO CASO substituir text/html; para json...