Google Sign-in doesn't work when AppCheck is enabled

[rscotten]

[REQUIRED] Describe your environment

• Operating System version: MacOS 13.1
• Browser version: Chrome 120.0.6099.109
• Firebase UI version: 6.0.0
• Firebase SDK version: 9.23.0

[REQUIRED] Describe the problem

Steps to reproduce:

Enabling AppCheck for Firebase Authentication breaks the Google Sign-in. Both the "popup" and "redirect" signIn flows don't work.

Relevant Code:

Just enable AppCheck for Firebase Authentication on your firebase project and see that the Google SignIn function doesn't work. I haven't tested on other providers.