Google Sign-in

Google Sign-in expects two valid strings, namely an Email address and a valid password. Once the user enters the valid Google credentials, the application is ready to fetch the information required to create an account or sign in the user. In the event of adding Google Sign-in to our projects, we need to ensure that we have obtained the SHA-1 fingerprint from the developer's computer and enabling Google Sign-in as the Sign-in method in the Firebase console. 

Once we have these two things in place, the rest of the process is pretty straightforward since we have already worked with email authentication using FirebaseUI.