audio: hal: Fix cts-on-gsi test failure

With GSI, voip rx path is opened at bootup time. Due to
this pcm config is left unset with zero initialized pcm config
causing failure when vts test client tries to create voip track.

This change is to set valid pcm config, thereby sending out
valid pcm config values whenever the client requests even if
voip call is not started.

Change-Id: Ic36faea1f5599703a05f515d30354908015ecc36