sysui: Observe wakefulness for smartspace.

  Instead of having the smartspace views observe screen
  on/off events. Have the lockscreen smartspace controller
  observe those events through the wakefulnesslifecycle and
  propagate it to the smartspace views.

Bug: 265931274
Flag: None
Test: Manual, atest
Change-Id: I82cf44ec2fa54dfcba7c768a03ccbfaebe9563c3