Code review comment for lp://staging/~ken-vandine/ubuntu-system-settings/bluetooth_lp1535660

While researching this I had a quick browse through the Bluetooth LE HID spec. Those devices, at least, can provide an icon specific to the device. I don't know how many of them do, and whether they're high-quality enough to bother with. But if the answers are "most" and "usually", we might end up rarely showing the device type icon anyway.