vrwm: Handle intents launched by the VR app

This gives us the following cases
Same appid, vr mode = 1: normal use
Same appid, vr mode = 0: VR app 2D intent
Different appid, vr mode = 1: Switching apps
Different appid, vr mode = 0: 2D app

Bug: 37099690
Test: Manual with calculator and oobetest
Change-Id: I7ba6588fb80d4c8de4f1372d047682f1d5d54860