fb: allow navring to show without assisten application

this commit adresses two problems

1. If the user does not install google now eg the navring does not
show up anymore even when other targets are assigned. Due that we moved
the disable/enable controll completley into searchpanelview which
calls DelegateHelper to disable it we just can remove the check
here in BaseStatusbar

2. On camera widget the navring is disabled and gets enabled afterwards.
This is of course a problem if we do not have targets assigned at all.
To fix it check for existend targets on the navigation ring

Change-Id: I1aa83fc8274995d9c1e9b88c76977977589502a6
fb: cleanup and let the navring stay and not

dimiss on targetchange....user seems to like it more
this way.

Change-Id: I73b36ef7a09dc08615fef522a8913a53b27b4763