leaudio: Allow to configure AF for more than 16kHz for Microphone

With this patch, if LeAudio group supports more than 16kHz for the
Microphone in the CONVERSATIONAL scenario, bluetooth stack will
configure Audio Framework to receive best possible sample frequency.

Bug: 230550335
Test: atest --host bluetooth_le_audio_test
bluetooth_le_audio_client_test
Sponsor: @jpawlowski

Change-Id: I653f0fa414fbaf783e65e99210e47ab38dc6a700