I think we don't need separate ConditionalFeatures, because an application that supports one type of app menu item will support all of them. Maybe something like ConditionalFeature.APPLICATION_MENU will suffice.
In addition to that, I've looked at several other applications, and most of them have custom menu items in their app menu. This leads me to question the API of your proposed feature. Maybe we should allow developers to add any kind of menu item to the app menu, instead of hard-coding two particular items?
