Fixing duplicate/inconsistent definitions for model and callbacks

> 2 implementations for filtering workspace items
> 2 implementations for binding widgets
> duplicate logic for add and update appInfo

Change-Id: Id68a49926af398478deca8ac85ab1f22341a9449

src/com/android/launcher3/model/CacheDataUpdatedTask.java

@@ -77,7 +77,7 @@ public class CacheDataUpdatedTask extends BaseModelUpdateTask {
             scheduleCallbackTask(new CallbackTask() {
                 @Override
                 public void execute(Callbacks callbacks) {
-                    callbacks.bindAppsUpdated(updatedApps);
+                    callbacks.bindAppsAddedOrUpdated(updatedApps);
                 }
             });
         }