title: Firebase login with GCP service account
body: <p>I am trying to login to the Firebase Tools CLI with a GCP service account. I have the path to the service account credentials saved as <code>GOOGLE_APPLICATION_CREDENTIALS</code>. I have logged out of firebase with <code>firebase logout</code> and have tried to sign in with the service account with <code>firebase login --no-localhost</code> and <code>firebase login --no-localhost  --token $GOOGLE_APPLICATION_CREDENTIALS</code>. However in bother cases a web browser opens asking me to log in with my user account. How can I log in to firebase with a service account?</p>