[Chipbar] Update ChipbarCoordinator to have a generic API to display chipbars.

The API is defined by ChipbarInfo, which has a startIcon, text, and
optional endItem.

Updates the media ttt code to convert the existing state into the new
generic state.

Test: manual: Verify every media ttt state displays correctly.
Test: atest MediaTttSenderCoordinatorTest
Test: atest ChipbarCoordinatorTest
Change-Id: I98c377cb9b416e051c747fe6d8553cfaa0724635