NetworkController: Extra WIMAX icon handling

- Fixes the dependency on 3g (or other mobile data)
  being connected for the wimax (4G) icon to show.
- Prevents the lack of mobile data (3g, 1x, etc) from
  removing the wimax icon if wimax is connected.
- Continue to show the network carrier type if
  phone is out of service but wimax is still connected.

Authored by: Matt Merhar

Change-Id: Ib1cf411cf4e7248248e093b6a7317fbe5d80f704