actions [{title: string, icon: optionalImageSource, show: enum('always', 'ifRoom', 'never'), showWithText: bool}]
Sets possible actions on the toolbar as part of the action menu. These are displayed as icons or text on the right side of the widget. If they don't fit they are placed in an 'overflow' menu.
This property takes an array of objects, where each object has the following keys:
title: required, the title of this action
icon: the icon for this action, e.g. require('./some_icon.png')