Do not always skip preparing window to display when already visible.

The window flag FLAG_TURN_SCREEN_ON relies on this method to properly
flag the screen to turn on. An optimization was put in place to skip
this method when the window was already visible. As a result, we would
skip turning the screen on if the activity was recreated.

This changelist addresses this issue by causing this method to execute
always if the flag is set.

Change-Id: I82c05c66136f7cc252b8d574d305809d455732ce
Fixes: 37432034
Test: bit FrameworksServicesTests:com.android.server.wm.WindowStateTests#testPrepareWindowToDisplayDuringRelayout
Test: go/wm-smoke