1. It is hard to predict that how long the Syrian government can survive. Unlike Russia, China has no strong interest in Syria. China will not support a falling government.
2. If China decides to involve, it is to control ISIS so that it will not become problems to northwestern part of China However, Russia is to prevent the collapse of the current Syrian government while US does not want ISIS to fall before the Syria government fell. According to China's military ability to delivere power at such long distance, China can not involve in with its own agenda. There, any supports to Russia is indirect.
3. China does not want to make enemy to any sides involved in the Mid East conflicts evidenced by the mild treatments to pirates in the escorting operations in Sea of Aden.
4. No. 16 will be truly used for training and scientific research before its 2nd aircraft carrier is in service. China could send No. 16 on friendly visits while training the ability to deliver power to long distance. It is just too risky to involve the insufficiently equipped carrier with insufficiently trained crew in real fights.