Your phone will be a brick for the entirety of your stay. A vpn is the only way to access google services in china.
Unless your goal is to read about Tiananmen Square in Tiananmen Square. Which just doesn't sound smart.
Obviously, it's different if you live there. But on a two-week vacation it doesn't seem worth it.
Plus without gmail, you can't recover a password or in some cases authorise yourself on 3rd party services.
It was a brick.