Disable pinning popup when transient taskbar is disabled

On freeform displays where taskbar is always pinned, toggling "Always
show taskbar" option is no-op, as the taskbar won't transition to
transient taskbar.
Left a TODO to reevaluate behavior once desktop taskbar transient
behavior gets updated.

Bug: 390665752
Flag: com.android.window.flags.enable_desktop_taskbar_on_freeform_displays
Test: Manual.

Change-Id: Icfe7cd26e77de48ab34bfe4932bfedfe21923ef1

quickstep/src/com/android/launcher3/taskbar/TaskbarControllers.java

@@ -248,6 +248,7 @@ public class TaskbarControllers {
         }, () -> uiController.onBubbleBarLocationUpdated(null));
         // Notify that the ui controller has changed
         navbarButtonsViewController.onUiControllerChanged();
+        taskbarViewController.onUiControllerChanged();
     }
 
     @Nullable