Ignore invalid combination of PowerManager flags.

ACQUIRE_CAUSES_WAKEUP is supposed to be ignored if combined with
PARTIAL_WAKE_LOCK. Instead it was being carried out for any values
of the WakeLock level.

This change reverts behavior to closely match
previous releases of the framework by only honoring
ACQUIRE_CAUSES_WAKEUP for screen wake lock levels. The only
difference being that in previous releases ACQUIRE_ could have been
combined with PROXIMITY_SCREEN_OFF_WAKE_LOCK (it never was) and
now such a combination will ignore the ACQUIRE_ flag.

Bug 7532258 fixed.

Change-Id: I46e848d8fd1b57e54c63141bf3d4f353986b5bdf