PhoneWindowManager: Fix screen peek KEY_FOCUS handling

* This addresses following issues where screen gets
  turned back off after turning it on:
  - User has screen peek disabled and presses KEY_FOCUS
    while their device is locked and screen is off.
  - User has screen peek enabled and presses KEY_FOCUS
    while their device is unlocked and screen is on
    then locks their device.

Change-Id: I92abc3c54747de3cc480ccd748885d80ba4a343a