audio/aidl/vts: Fix impossible to met config requirements

The default audio set configurations json file has no
asymmetric 16/8kHz config for Game audio context. However
there is a valid entry for 32/16kHz - use that for the
asymmetric configuration request.

Bug: 395453363
Test: atest VtsHalBluetoothAudioTargetTest
Flag: Exempt; day2day fix, test only change
Change-Id: If45f8751043ac0d446e1b5697587e6c3c41b3ea8