Spatial Audio: Log head tracking velocity in degrees / s

Head tracking velocity is given as the intrinsic axis * (dangle / dt).
We express this as degrees/s with d_pitch, d_roll, d_yaw.

Cleanup of the VectorRecorder index offset and add delimiters.

Test: adb shell dumpsys media.audio_policy
Bug: 270763710
Change-Id: I64a194a9b839567529c0359c2ebe3a78d89e7c61