audiopolicy: engine: Add VTS for engine configurable configuration

This CL adds VTS test for engine PFW configuration files (Skipped
for default engine, the check is performed by reading the
audio_policy_configuration file AND parameter-framework top configuration
file)

AllSchemas.xsd is made by manual inclusion from all other
xsd files. It is used for API files generation.

Test: build & run vts --module VtsHalAudioPolicyV1_0Target
      atest VtsHalAudioPolicyV1_0TargetTest
Bug: 141989952

Change-Id: I62730caadafdcb5ebb3083d683625424864afe97
Signed-off-by: François Gaffie <francois.gaffie@renault.com>