SetupWizard improvement: let users see "scanning"

Current UI shows nothing when there's no connection available, even when
the device is finding some. So user cannot know whether the static
"Not connected" screen means: the device is finding right now, or
actually no network is available.

Change-Id: Ia8ea1c66956e8de819f6a98362bcc9086bda172c
3 files changed