Compatibility when hosting via Firebase Functions

[benjaminben]

Thanks so much for this very helpful example repo. I wanted to leave a note here (since it was where I initially searched for the solution) that the cookie name token is not compatible as of writing with Firebase's experimental support for turnkey Next.js deployments. This is because Firebase Functions only accept one cookie by the name of __session. (SO source) While the example provided in this repo worked fine in development, the call to firebaseAdmin.auth().verifyIdToken(cookies.token) would fail in production due to Firebase stripping the token cookie. I switched the saved cookie's name to __session in both the AuthProvider and in authenticated.tsx and that resolved the issue for me, not sure if there are any potential pitfalls of doing this.