open override fun onBackPressed(): Boolean
Called as a result from pressing a hardware back button. This should only be called as a result of user interaction with a back button, and not to trigger behaviour that is assumed to result from a back press. For example, in order to go back in a task panel back stack, do not call this but close the panel directly using TaskPanel.dismiss instead.
true to indicate that the back press has been consumed and should not be propagated to other consumers.