Bug 1037880 - FM radio should stop sound in speaker mode when I receive ...

...an incoming call
So what will happen for such a case:
  - User opened FM radio app.
  - User turned off the FM radio, but leave the app opened.
  - A call is coming, user picked up the call and hang up in a minute.
? Will the setting |private.broadcast.attention_screen_opening| be changed and FM radio is enabled?