base: Fix screen on stats after a boot

Prior to this change, the following sequence:

  * Turn the display off
  * Issue a reboot via adb
  * Unlock the device (after rebooting) before the screen turns off

results in the screen being on but the battery stats not reflecting
this fact.

In general, the mismatch occurs when either there is no serialized
battery stats state or when it is serialized in a state where the
screen is off.

Change-Id: I17374553fae6a08a1be8fdf445967509474177a9