Add PulseAudio move skins command

Summary:
This is intended for workstations to plug an USB headset and redirect
the output to this headset (or a contrario to redirect back to main
speaker).

Test Plan: Tested on graywell and orin.

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D1143