Fix ambient display

Due to a refactoring for touch, wake and unlock for fingerprint
devices PhoneWindowManager now waits for Keyguard to draw its first
frame in all cases, including when screen turns on for pulsing.
However, since in this case the device is not awake, we need to check
for screen on instead of awakeness when proceeding with the wake-up
sequence. Without this change, screen on was blocked forever in the
pulsing case.

Bug: 22605235
Change-Id: Ib6089fd14b673e62347f2c9108d9a6783caa26b7