on Android 5.0.2 the automatic filling for Chrome is working, but on Firefox manual filling is available only. Do you know this? Hopfully you bring an update soon.
As mentioned in our sticky post in the Android Beta channel, automatic filling and login detection is only supported on Chrome, Javelin and Opera browsers at the moment. There are few challenges with the other browsers, including Firefox, so you will need to use the manual filling feature there instead. We do plan to look into supporting additional browsers as we continue to improve the filling functionality and we certainly want to support Firefox as it's one of the popular browsers on Android.