Install Google's gboard & restrict any network access that the app has.
Same deal with the camera & photo gallery.
Discussion
I read about this specific point and that by the time I restrict it, it would have already sent out my private info.
Not sure how true that is but that's why I avoided installing GBoard.
Your keyboard has no reason to connect to the outside world but it sees everything you type and copy/paste. It should be isolated anyway - may as well have a good one.
Same for the camera & gallery apps.
To do it:
- long press on the App & tap App info
- tap Permissions
- remove all but sensor access
When you install any app in grapheneos you will have an option to restrict network prior opening the app for the first time