Binding Taskbar directly from Launcher model

This allows taskbar to be loaded even in case of 3P Launchers
and removes dependency on LauncherActivity lifecycle

Bug: 187353581
Bug: 188788621
Test: Manual
Change-Id: I5a0988e0697b41677d4c58f0213aef14ec0c0972

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

@@ -85,5 +85,6 @@ public class TaskbarControllers {
         rotationButtonController.onDestroy();
         taskbarDragLayerController.onDestroy();
         taskbarKeyguardController.onDestroy();
+        taskbarViewController.onDestroy();
     }
 }