HDMI: On TV panels if DSM is enabled do not allocate an audio system

Dynamic soundbar mode is a feature specific to source devices. This setting can be toggled on TV panels with adb commands with the result of adding an audio system to the list of local devices. This can lead to unwanted behaviors.

Flag: EXEMPT bugfix
Test: m && atest com.android.server.hdmi
Bug: 367478115

Change-Id: I8f302de1e5a96a77ada6200f4bba8aa280004ec7