LeAudio: Extend the context alignment policy

In the local source metadata update the context alignment
policy did not take into the account that some of the
bidirectional contexts are only notified on the sink metadata
update event.

Test:  atest --host bluetooth_le_audio_client_test bluetooth_le_audio_test --no-bazel-mode
Change-Id: Ice7bce2640ecd069b24e6f77aae82f5eceef7a35