`_getCurrentStatus` is called in two places : `setEnabled` and `getStatus`.

These two API are called by developers and they need to know the latest status and do further stuffs. 

While for `addObserver`, this is to monitor changes from system app and try to call added callbacks.

I think they are not related to each other and there is no place to cache status. If I misunderstand your meaning, please correct me.

Thanks Arthur :dango: