Better solution for updating configurations

[ChunyiLyu]

Is your feature request related to a problem? Please describe.

At the moment, the controller uses configMap update as the signal to decide to trigger a statefulSet restart. This approach is very cheap, but has it's downside. If the statefulSet restart was not successful at first reconcile time, even if we requeue the same request, configMap no long needs an update and the controller will not try to restart the statefulSet. We need a better solution so that the restart can be trigger reliably.