Revert behavior of Lockscreen Activity Launch to KK

There exists a lifecycle regression where launching an
app from the lockscreen (camera, etc.) causes a series
of onResume, onPause, onRestart, onStart, onResume.

This CL reverts the behavior to what it was in KK, which
is to say that the Launcher is first resumed/paused, then
the Activity being launched has a simple onRestart,onStart, onResume
lifecycle.

Bug:17459745
Change-Id: I04091d2f86a929ee972c8d6debc1beb033c135a8