[Output Switcher] Add suport for subtext and ongoing session

Add support for device with subtext, set click action based on selection
behavior and provide status icon based on subtext.
For ongoing session, currently only support participant, which not allow
volume control.
Enable feature flag in this branch for following up testing.

Test: atest MediaOutputAdapterTest MediaOutputControllerTest MediaOutputBaseDialogTest MediaOutputDialogTest
Bug: 260021936
Bug: 260010689
Bug: 262013662
Change-Id: I93619a76eeaacc8fbde2b5eca2fff6e6b87b55a4