starting camera position is different in Unity XR player vs. WebVR export

[cvan]

see this comment I made in @caseyyee's PR #295: #295 (comment)

something in here caused the default camera position to be different (compare it to the position in master)

with eb01ad3 (previously master)

in this branch

related issues:

• Viewpoint is underground when using Oculus XR Settings #284 for XR player for Oculus

• Doesn't always start a right elevation in Windows MR #102 for WebVR export for Windows Mixed Reality

• [meta] Camera rigging #154 for general improvements to the camera, specifically, per @delapuente:

  During design time, there should be only one camera in the scene hierarchy. The camera is doubled in gameplay.

  Most of the items were implemented in Calculating transform parameters instead of overriding worldToCameraMatrix #159 . Changing the camera rigging to a unique camera duplicated in runtime feels like a considerable change in the way the prefab is used. Furthermore, SteamVR Plugin also supports a stereo + mono camera rigging. I think this needs further discussion.

[caseyyee]

Seems to work for me now. Reopen if you encounter this issue again!