dronelistObserver onChange() fires and action is taken. I no longer have need for the Observer in the current Activity and I do not want to rely on the Activity lifecycle to manage suspending / resuming it.
When you request something observable from groundsdk APIs and provide a Ref.Observer<T> of some kind, as in your code sample, you get a Ref<T> in return.
This is basically your hook onto both the observed data (you can call get() on it to fetch current data) but more importantly also onto the observer itself: you can use Ref.close() method to unsubscribe from observer change notifications. Once you call close(), your observer won’t be called anymore.