These are not being used yet in Taskbar, but they are hardcoding
DEFAULT_DISPLAY for the primary ID. In tests, we want the primary to be
considered the ID of the virtual display tests are running on.
This change also moves dagger classes to its own file for organization.
Flag: TEST_ONLY
Bug: 415326979
Test: Taskbar multivalent tests
Change-Id: Ibd0cdf46bc53dbd7a3dd5f34d7171d9a6cdebb38