MSD: Add HW A/V Sync flag for the output connection from MSD

This is recommended for TV confugrations.

Bug: 63901775
Bug: 111746865
Test: MSD prototype with surround and stereo-only sinks
Change-Id: Ia3e0d077f41bcee8e3b0ee05838d023f4572b66f
(cherry picked from commit 726c9947933ed4a9153c56d8e3b5d0757ee03144)