Google has updated their Google Authenticator mobile app for Android devices. The latest app no longer require QR code scanning or password entry for connectivity.

Google would connect the app to your account and let you enable 2 factor authentication to it without any manual processing.

Google said:

Turn on 2-step verification for your Google Account without having to scan a QR code or re-enter your password on this device. If you’re not already using 2-step verification, start by visiting the security settings for your Google Account to see if this new setup flow is enabled for you. New permissions are required to update your Google Account credentials on this device when you set up 2-step verification.