Tapping on an active tab should reset the current state in that tab for all nested navigators, recursively.
Currently it calls popToTop() if a StackNavigator is inside the tab. However, this doesn't have the desired effect on a nested DrawerNavigator, SwitchNavigator, or a combination of multiple nested navigators.
(I have a StackNavigator in a DrawerNavigator in a TabNavigator. I want a tap on the active tab to reset the StackNavigator and the DrawerNavigator.)