Change icon for navbar task for contextual buttons.

The navigation bar customization is awesome.

I've added a button to my nav bar that is contextual.  Pressing it triggers a task that behaves differently depending on where I am, what network I'm connected to, what app I have open, and possibly more.  For example, if I'm not at home, it toggles my media play/pause.  When I'm at home, it toggles my lights on and off.  When I'm connected to my grocery store's wifi, it opens up Samsung pay.

I would like to be able to dynamically change the task's image in the navigation bar.  This way I can make it clear what it will do when I press it.