I am glad that it helped you. Let me answer your questions one by one.

Question — I noticed that the “SERVER_CLIENT_ID” is included in the code. Do we also need to include the Android Client Id somewhere?

Answer — It is not recommended to keep any type of secret id in the source code that gonna stay in your

your git history. So I would recommend using the Secrets Gradle plugin (https://developers.google.com/maps/documentation/places/android-sdk/secrets-gradle-plugin).

Question: what does “SignUpFormActiivty” refer to in the following line?

Answer — Google sign-in gives you associated user info that you can use for sign-up flow according to your server.

Does this refer to the name of the main class in the project?

No, It is related to user management on your server.