Thank you for contacting us,
We reviewed your comment, however, was unable to recreate this behavior while using latest NativeScript CLI 3.4. Could you provide again the exact error, which is returned from Google as well as some more info about your environment(CLI, modules, runtime versions)?
In the meantime, I would suggest trying generating a new certificate and to try signing the app again.
Also, could you provide info if the suggestion provided by Dimitar resolves the case?
Let me know if I could assist you further.