[keycloak-dev] Revert changing from Google Authenticator to FreeOTP

[Stian Thorgersen]

I'm not a big fan of the recent change from Google Authenticator to FreeOTP.

* Google Authenticator is far more widely used than FreeOTP
* We have existing users that use Google Authenticator (we know it works for both, but they and their users don't)

To support FreeOTP we need to add support for multiple OTP providers so developers/users themselves can choose between the providers, not us.