Any half-decent environment would not permit an app to receive an update to its code that has not gone through the same process as the original code went through i.e. the process as far as submission to the store and the checks that G/A make. Otherwise this would be a loophole big enough to drive a bus through.
Also, an app probably doesn’t control its own updating i.e. updating is centralised through the store. There is user convenience in that, as well as developer convenience.
Bring no phones. Any phone that is handed over to the authorities as you enter the country is potentially compromised. If you have to bring a phone (e.g. for compliance) then bring one burner phone.
I wouldn’t recommend playing games with the Chinese government.
- they don’t have a sense of humour
- they are better resourced than you
- they are probably smarter than you
This may have been a thought experiment but no foreign spectators are allowed. Noone is travelling to the Beijing Winter Olympics with friends.
Sometimes that will work, sometimes it won’t. Believe it or not, the Chinese government knows about these. Many VPN services will simply be blocked. Any traffic that looks like VPN will likely be detected and then potentially blocked. But, OK, if you run your own VPN server, solely for your use, and it is set up carefully, you may get away with it.