[Chipbar] Move the Media TTT callback listener to a media-specific
coordinator class.

Bug: 245610654
Test: manual: Verify media ttt sender and receiver commands still work
Test: atest MediaTttSenderCoordinatorTest
Test: atest ChipbarCoordinatorTest
Change-Id: I28706e2e7c61c049575c5c2dfca6844f5820f001
7 files changed