HDMICEC: Remove local device Audio System from mLocalDevicesTypes

When CEC is initialized on the DUT, the list mLocalDevicesTypes is used
to get the types of local devices to be allocated.

Using this list inside the HdmiControlService's constructor for unit tests was introduced by the change ag/20257160.

A local device of type Audio System shouldn't be allocated for each tests, the <Report Features> tests being the only tests requiring this.

This change impacts the Dynamic Soundbar mode's unit tests where
it is expected for a local device Audio System to be included or
removed from the network after CEC initialization.

Bug: 256567948
Test: make && atest HdmiControlServiceTest
Change-Id: I16535b1ce077b38411f31bfc41d18e7734fcedac