Add flag-disabled test to PresentationControllerTests

Currently the differnces between flag on and off are:
- Apps behind a presentation stop.
- Shell transitions run.

Flag: com.android.window.flags.enable_presentation_for_connected_displays
Bug: 390482872
Test: WmTests:PresentationControllerTests
Change-Id: I436e116c25ec7b86dd065c9f2bcbebd14e122de6