Move VR Display Policy check to after wakefulness.

Being in VR was preventing sleep and doze functionalities to function.
Sleep and doze is what commonly happens when the user hits power button
and without this fix hitting the power button resulted in PowerManager
not turning off the display.

Bug: 65635259
Test: Manual.  Ensure that hitting power button while in 2D-in-VR turns
screen off on smartphones.
Test: runtest --path
frameworks/base/services/tests/servicestests/src/com/android/server/power/PowerManagerServiceTest.java

Change-Id: If3a14a5a423b0394926b323b97ed11b98177e43b