Oculus’ Mobile SDK has a video capturing feature, that greatly simplify the making of promotional videos for games that target GearVR platform - https://developer.oculus.com/documentation/mobilesdk/latest/concepts/mobile-testing-capture/.
When video capturing is enabled on device, app crashes on start with “eglMakeCurrent:980 error 3009 (EGL_BAD_MATCH)” error in logs which indicates draw surface size mismatch. I think the reason is single-eye rendering mode, enabled by video capturing, and Unity is not ready to that.
Here’s a bug https://fogbugz.unity3d.com/default.asp?770237_l6f2jk4tfep51qet
reproduces on 5.3.2p3 with Samsung Galaxy S6
I hope Unity’s VR team will look into it, since making videos without this feature supported is too complicated.