leaudio: Use common CCID keeper in unicast and broadcast

Broadcast source needs to access the same CCID information
as the unicast client.

Bug: 150670922
Bug: 230340466
Tag: #feature
Sponsor: jpawlowski@
Test: atest LeAudioBroadcastServiceTest bluetooth_test_broadcaster_sm bluetooth_test_broadcaster bluetooth_le_audio_client_test
Change-Id: I109d599ddac080fa2919ef586aa4510e4ab6fe8a