[1/n] Order DesktopModeLoggerTransitionObserver after desk transition

This is to ensure the session is logged as active from desk transitions
so task update is logged after session update.

Flag: EXEMPT refactor
Bug: 423560267
Test: atest DesktopInOrderTransitionObserverTest
      atest FreeformTaskTransitionObserverTest
Change-Id: I9f1f978aabe90b830fb6b59f9879c87942a048d5