Bug 1064256 - [Contacts] "TypeError: iceGroup is null" r=sergi

In what situation would `iceGroup` be null? Could we just always create it?

Also, wouldn't it be better to make the check in `hideICEGroup`? Like

```javascript
function hideICEGroup() {
  if (!iceGroup) return;
  
  iceGroup.classList.add('hide');
  utils.alphaScroll.hideGroup('ice');
}
```