Merge "Fall back to system DEFAULT_DISPLAY on disconnect if needed." into main

    /** Start a disconnect transition directly in Shell. */

    fun disconnectDisplay(disconnectedDisplayId: Int) {

        logD("disconnectDisplay: disconnectedDisplayId=$disconnectedDisplayId")

        val disconnectReparentDisplay =

        var disconnectReparentDisplay =

            UserManager.get(userProfileContexts.userContext).mainDisplayIdAssignedToUser

        // If user has no default display configured, fall back to DEFAULT_DISPLAY

        if (disconnectReparentDisplay == INVALID_DISPLAY) {

            disconnectReparentDisplay = DEFAULT_DISPLAY

        }

        val wct = WindowContainerTransaction()

        val runOnTransitStart =

            addOnDisplayDisconnectChanges(wct, disconnectedDisplayId, disconnectReparentDisplay)