fb: actually fix LTE toggle (2/2)

I accidentally pushed the LTE toggle patch although it was not ready.
Whatever here the fix for it. This commit does:

- do not assume that on boot ITelephony service is already up. This
  results in a FC on boot up
- handle like before most things in LTETile itself and call only
  the toggle action to prevend above mentioned
- I thought about it to give as parameter current network state
  to the toggle method to prevend to fetch 2 times the actual mode
  (saves 4 lines of code). But based on the idea that we maybe later
  use other shortcuts as well we will not do it.
- cleanup & codestyle

Sorry again

cheers

Change-Id: I9b0e304000e1c042955c8d14c50d8cd34cbc1327