Velocity Tracker doesn't account for play space velocity (unlike tutorial version)

[Ian McClellan]

The OVRAnchorVelocityEstimator.cs looks like an older version of the script as it does not account for playspace velocity as is done in the tutorial version, see ExtendRealityLtd/VRTK.Tutorials.OculusIntegration@135e801

[extendreality]

Fixed with #16