[OutputSwitcher] Fix routes will show selectable when LE Audio broadcasting...

[OutputSwitcher] Fix routes will show selectable when LE Audio broadcasting feature is not supported

Existing codes do not check if broadcasting features are supported (e.g. for older pixel devices or override in developer options).

Bug: 428082818
Test: Manual
Flag: EXEMPT bug fix

Change-Id: I558fee2aacd5e67b79503273cc197cff1b9770bb