leaudio: Send codec config just before device is ACTIVE

This patch makes sure that before device is Connected to Audio Framework
(device is ACTIVE), LeAudioService knows currect codec configuration.

Also, when currect codec configuration changes, AF is notified

Bug: 314094343
Bug: 326442537
Test: atest LeAudioServiceTest bluetooth_le_audio_client_test
Change-Id: I01e1850c8c3992fc57e58398b2fef33d23050690