Align policy xml example with xsd

The xml example contained an intel extension (htmi HAL) that is no longer
allowed after trebbleisation.

Additionally a route was specified twice which is not allowed.

Bug: 38184704
Test: xmllint --noout --xinclude --schema hardware/interfaces/audio/2.0/config/audio_policy_configuration.xsd frameworks/av/services/audiopolicy/config/audio_policy_configuration.xml
Change-Id: I56c3a38c840bf7757f4667cec103ad212531b071
Signed-off-by: Kevin Rocard <krocard@google.com>