I created an Android project on Google dev console using debug SHA1 fingerprint and also generated google-services.json file using same debug SHA1 fingerprint for by Google oauth2 implementation. Everything works fine. To upload the app to Google Play, I created one more project on Google dev console with release keystore SHA1 fingerprint and did not generate google-service.json. However, app is working fine even in release mode and I am able to do Google login in my app.
So what exactly is the use of google-services.json file? Should I create a new google-service.json file for release mode and how is it working even without it? That file has client_id of Android project that I created with debug SHA1 fingerprint.
I have checked both these links - link1 and link2 but did not find any answers satisfying. Thanks.