Wake the screen if the proximity wakelock is released while the proximity sensor is active.

This fixes a problem that resulted in the screen staying off indefinitely if the prox sensor
is active at the beginning of a bluetooth call and could result in the screen staying off
in other similar circumstances.

Change-Id: Icfa0046d3179f9bb2247e7a3c1f9ff073312667a
Signed-off-by: Mike Lockwood <lockwood@android.com>