Make default USB handling apps per profile group.

If a USB device is plugged in a default app might be started. As the
user does not indicate which profile he is interested in by pluggin in a
USB device, all handling of this operation has to be per default group.

To do this Split UsbUserSettingsManager into UsbUserSettingsManager and
UsbProfileGroupSettingsManager and modify
UsbProfileGroupSettingsManager.

Bug: 29233186
Change-Id: I8e56b621eeb802966504360d372a8a0140106114