Fix when vr app launches 2d activity

When a 2D app is launched from a VR app, since the VR app was on
DEFAULT_DISPLAY, the 2D app is also moved to DEFAULT_DISPLAY. This needs
to be addressed by moving any non-VR 2D app launch in VR mode to the
virtual display.

Bug: 37111307
Test: android.server.cts.ActivityManagerDisplayTests
Test: #testVrActivityLaunch
Test: #testVrActivityReLaunch
Test: #testPostVrLaunch

Change-Id: I83bffe94bb89415a6b3c026dd7077e70fe36fee0
Signed-off-by: Karthik Ravi Shankar <karthikrs@google.com>