Extend recents button hitbox on tablet

* Extends hitbox when recents is tapped
when going from taskbar to overview.
* Extended region lasts for 400ms after
the animation ends.

Fixes: 225885714
Test: Manual, added unit test
Change-Id: I8766279c1a5bf6867f8d69ddd3af2aa3565deec2

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

@@ -182,7 +182,8 @@ public class TaskbarDragLayerController implements TaskbarControllers.LoggableTa
          */
         public TouchController[] getTouchControllers() {
             return new TouchController[]{mActivity.getDragController(),
-                    mControllers.taskbarForceVisibleImmersiveController};
+                    mControllers.taskbarForceVisibleImmersiveController,
+                    mControllers.navbarButtonsViewController.getTouchController()};
         }
     }
 }