Floss: add codec type parameter to |set_audio_config|

In this CL, we change the parameter in |set_audio_config| to allow
configuring the codec type at the same time of deciding the detailed
configurations (e.g., format, rate).

Bug: 268424393
Tag: #floss
Test: atest net_test_stack_a2dp_native
Change-Id: Ie8e44a68b46c0cc1079b063a58f64b2228169084