Set controllersInitialized to false when destroying taskbar controllers

Bug: 250912179
Test: presubmit
Change-Id: I16532e99b8f74542def4283b6cc753673eb5ee2d

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

@@ -165,6 +165,7 @@ public class TaskbarControllers {
      * Cleans up all controllers.
      */
     public void onDestroy() {
+        mAreAllControllersInitialized = false;
         mSharedState = null;
 
         navbarButtonsViewController.onDestroy();