Destabilizing the region isn't in India's benefit. In any real war they would be destroyed by China. They have even started to talk to Pakistan again. Given that they could talk to Pakistan, china would in turn back off them. A missile test would only anger the Chinese and make the Pakistanis back out of talks. This is a lose, lose situation and doesn't make any sense. considering India has more than a capable armed force that can deal with Pakistan.