Consolidate the logic for "Connected" and "Selected" states.

- Fixed "Go to app expandable" (having both "go to app" link an a group
 status) scenario in b/355062931. Previously, the branch for "Selected"
 device didn't set the group status.
- `mController.isCurrentConnectedDeviceRemote()` replaced by
`isSelected` for the Selected scenario.
- Additionally, consolidated the "Disconnected" state.

Flag: EXEMPT refactor
Bug: 355062931, 387570618
Test: atest SystemUiRoboTests:MediaOutputAdapterTest
    atest SystemUIGoogleRoboRNGTests:MediaOutputAdapterScreenshotTest
Change-Id: Icbbe049ee9f10dc9c915ce0fd095236bf991d1f3