audio: Verify that VTS tests can work with vendor extensions

Vendors can have vendor-extended device types and
audio formats supported by their HALs and frameworks.
VTS tests are built using AOSP sources, thus they don't
have these vendor modifications. Ensure that VTS tests
behave correctly when dealing with audio policy manager
configurations that contain vendor extensions.

Since verifying this behavior requires using specially
crafted APM configs, verification is done using
unit tests.

Test: atest HalAudioV6_0GeneratorTest
Test: atest HalAudioV7_0GeneratorTest
Change-Id: I9dc1a18863418a8fbd7d1dc14abc844fd9060ca5