Add dynamic group operation in output switcher

-Add MediaOutputGroupAdapter for device view layout
-Add MediaOutputGroupDialog for dialog header and buttom
-Add test cases

Bug: 155822415
Test: atest MediaOutputAdapterTest MediaOutputControllerTest MediaOutputBaseDialogTest MediaOutputDialogTest MediaOutputGroupAdapterTest MediaOutputGroupDialogTest
Merged-In: I82b52485229b7aa8b80a6ef13fc9aac14af87446
Change-Id: I82b52485229b7aa8b80a6ef13fc9aac14af87446