Assuming you are using 2.7... you have full control over ALL fields. Go to fields management, edit the Country field. Add (or remove) whatever countries you need. I see China is in the list of countries loaded on install. Hong Kong was missing so I'm adding it for the next package. Still, you can modify this at anytime. Then when you uninstall/reinstall for upgrades, your country list will remain in the database and not need modified again.
I didn't make myself clear, I am using 2.7.1d. The countries dropdown which I am referring to is the one in location manager. I still can't see China and Hong Kong after adding them in fields manager.