I am following this link to integrate Google sign-in in my android app.https://developers.google.com/identity/sign-in/android/start-integrating
As given in last step on the
This error comes up when there is change in your config.xml file resulting in mismatching of the data present in google-services.json file.
I got it fixed this just by updating changes to my google-services.json file and building the app again ...it worked well.