[le audio] Update broadcast audio quality per sinks capabilities

If any connected broadcast receivers could not support HIGH quality,
framework will downgrade the broadcast audio quality to STANDARD.

This change only applied to broadcast feature function which is behind the feature flag.

Bug: 325644399
Bug: 316005152
Test: atest LeAudioBroadcastServiceTest
Test: manual test broadcast
Change-Id: If39a904c942c27c7749147ec97a78162aba97b88