Disable double haptic when dragging from taskbar hotseat on home

Both DragLayer and the dragged view were playing a haptic; disable
DragLayer's haptic feedback for this drag interaction.

Test: Drag from hotseat on home, ensure only one haptic is played
Bug: 182079330
Bug: 171917176
Change-Id: I185533999e905ea79a80aaa2145fc39049e8d45e
diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarDragListener.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarDragListener.java
index 9d203fb..dc27df1 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarDragListener.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarDragListener.java
@@ -56,11 +56,14 @@
     protected void init(DragLayer dragLayer) {
         mDragLayer = dragLayer;
         mDragLayer.setOnDragListener(this);
+        // Temporarily disable haptics, as system will already play one when drag and drop starts.
+        mDragLayer.setHapticFeedbackEnabled(false);
     }
 
     private void cleanup() {
         mDragLayer.setOnDragListener(null);
         mLauncher.setNextWorkspaceDragOptions(null);
+        mDragLayer.setHapticFeedbackEnabled(true);
     }
 
     /**