Allow VRWM to show 2D apps

2D apps appear as a single app layer at the front of the stack. We can
distinguish them from VR apps as VR has two layers at the front.
When we detect a 2D app we don't skip the first layers for rendering

Test: launch VR app, launch calculator
Bug: None
Change-Id: Iea8420870852b84ab790b5185ac1a44103c2aae5