AUSTRALIA Television has doubled its news output in response to viewer demand. Paddy Conroy, director of television for Australian Broadcasting Corp said: ''Our success has been the result of one factor - we are pan-Asian and therefore very relevant. We also take Asia seriously, with 11 bureaus in the region.'' In Hong Kong, the new service opens at 7.30 am with the main Asian news bulletin. The changes have increased news and current affairs to about one third of total programming.