Audio HAL: Align V2 and V4 VTS

It was thought that the V2 VTS were not going to be supported after V4
VTS were created. Thus a large portion of the code was copy paste and
modified.

That assumption ended up wrong as a lot of OEM reported bugs that needed
to be fixed in both versions.

As a result align the code of both version VTS as much as possible.
The code will be merged in a follow up patch.

Bug: 118203066
Test: compile
Change-Id: I994232db237b5d7c52e7d796f199ab3c6eec21f4
Signed-off-by: Kevin Rocard <krocard@google.com>