perf: Don't persist the perf profile across a reboot

 * Always initialize with the default performance profile.
 * There are a lot of reasons for this, but mostly because
   users are stumbling into the setting and ending up with a
   slow system because they enabled powersave mode.

Change-Id: Icd0a1ddcc41700eb29a126bda1eb67a26fc2d5dd
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
Add CPU boosting hooks

 * Send boost hint during scrolling
 * Still relevant on even high-end hardware

Change-Id: I72f2c2851b01fbceabddead03a4c3a7a0526ca61