Add Media Output Dialog for Output Switcher

-Add MediaOutputBaseDialog to provide common method for different media operations UI
-Add MediaOutputDialog for showing Bluetooth device
-Add resources for background image, style and layout
-Add MediaOutputBaseDialogTest for unit test

Bug: 155822415
Test: atest MediaOutputBaseDialogTest
Merged-In: I3086a4049f240870ca1ad870946d6848e500b561
Change-Id: I3086a4049f240870ca1ad870946d6848e500b561