intelligence
intelligence run dnsmasq on the phone itself and set the dns to localhost
That's a great question. I did something similar on a nonrooted OnePlus phone. Before I switched to grapheneOS there was no way to truly disabled Google's connectivity check through Google's gstatic server.
But there was a system level setting to define the server. So I used Tasker and python to run a simple web server that returns the proper http code. It worked great.
Of course, a simple python web server is lightweight compared to dmsmasq. But should still be possible.