audio: Add audio_policy_configuration.xsd for the parser

The default implementation will include an XML APM config
parser generated from the XSD schema. This CL provides the
schema file. It was copied from HIDL/7.1 and augmented
with new formats.

Bug: 255477173
Test: N/A
Change-Id: Ic0a09ba044d87165441671a2b2601b0a8177e5fa