Indien as waar gemerk, word die custom_icon-sleutel gebruik as pasgemaakte ikoon vir die knoppie. Indien as vals gemerk, word die custom_icon-sleutel geïgnoreer. Hierdie sleutel is slegs relevant as die object_type-sleutel "menu-object" of "drawer-object" is.
If true, the custom_icon key is used as a custom icon for the button. If false, the custom_icon key is ignored. This key is only relevant if the object_type key is "menu-object" or "drawer-object".