while i was connecting firebase to my flutter project on android studio iam getting this error i have done all the setup they mentioned in the firebase installation section

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'android'.
> Could not resolve all files for configuration ':classpath'.
   > Cannot resolve external dependency com.google.gms:google-services:4.4.1 because no repositories are defined.
     Required by:
         project :