PEEK: Beautify bridging layers code

* Save new instances for Peek and PowerManager:
    Create it only in BaseStatusBar when start() method is called. That one
    will be passed throught the sub layers such like new helper class so another
    feature can check Peek state invocking from NotificationHelper class.
* Move phone listener to new helper class.
* Do not show Peek on sim pin lock screen.
* Process new incoming notifications only if screen is off.
* General cleanup.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Change-Id: I9efde073df35b92e42b9faa9930d2fc39b3a43b9