The error is:
File google-services.json is missing from module root folder. The Google Quickstart Plugin cannot function without it.
WINDOWS
(Alt+F12 or View->Tool Windows->Terminal).
Then type "move file_path/google-services.json app/"
without double quotes.
eg
move C:\Users\siva\Downloads\google-services.json app/
LINUX
scp file_path/google-services.json app/
eg:
scp '/home/developer/Desktop/google-services.json' 'app/'