I see that there’s a Google API for authentication, but is there an existing API for connecting to a Google Drive and reading/writing files? If so, what would be an appropriate way to sync Expo AsyncStorage with those files? If not, would it be possible to adapt a react-native component or similar?
The react-native link react-native-fs command in the installation instructions mean that it is a native module, so you would need to eject in order to use it.
But, there is apparently a JavaScript SDK, which means in theory you can use that from a managed (non-ejected) Expo app.
This Google search looks like it has several useful results.