LeAudio: Add upper tester flag for multiple CCID

This is needed to pass some of the qualification tests.

Bug: 240145685
Test: atest --host bluetooth_le_audio_test bluetooth_le_audio_client_test bluetooth_test_broadcaster_state_machine bluetooth_test_broadcaster --no-bazel-mode
Change-Id: I47eca845ee07cdabdf093389bc5810cf9eaf2d5b