Audio V4: do not override V4 audo policy config XSD

The xsd did not have its version in its name, thus the V4 and V2 were
overwriting each other.

Bug: 38184704
Test: vts-tradefed run commandAndExit vts --module VtsHalAudioV4_0Target
Change-Id: Id7e733729a9afcdcc582f88a5527b6eb1c7283bf
Signed-off-by: Kevin Rocard <krocard@google.com>