QS: Disable WifiDisplay tile

WiDi got replaced with a generic screencast remote display implementation
in 4.4.1, this needs to be replaced accordingly

Change-Id: I7ac28e25a97cbe05284664f8afdb6a1ab5cb71c0
Keyguard: fix statusbar lags when default widget shown.

When statusbar became expanded KeyguardStatusView receives
onKeyguardVisibilityChanged callback and refreshes ClockView.
Because it receives more than one call and every time it reads
new values from resources it cause lags in opening statusbar panel.

Replace this code with BroadcastReceiver and ContentObserver to
refresh it only in case something was changed.

Change-Id: If0dbc1db059536806852661931cb2e6436f2acf4