[Output Switcher] Refactor MediaOutputAdapter

re-arrange codebase, avoid duplicate code in Adapter layout update,
without affecting current usage.

Change-Id: If73f23166a206ad41b31b0b006ae20c62c78626a

Bug: 239383468
Test: atest MediaOutputAdapterTest MediaOutputControllerTest MediaOutputBaseDialogTest MediaOutputDialogTest
Change-Id: I80fd6fe388a2c2f47950af79d2d861dc5714a299
5 files changed