leaudio: set preferred codec config media test part 2

Adding unit test for api:SetCodecConfigPreference for all use cases
during media streaming.

Bug: 259191520
Bug: 353909820
Flag: TEST_ONLY
Test: atest bluetooth_le_audio_test bluetooth_le_audio_client_test
Change-Id: I2b2fd582df445d52efdcd2080646daaf110e8506