Moving all-apps predictions to Launcher model

Predictions are loaded and managed by Launcher model and follow
the model lifecycle. They are then bound to the callback which
handles the UI

Bug: 160748731
Change-Id: I4a3ea0698d80fafe94afb4ce66ffa7f4a6a91c68

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

@@ -108,13 +108,6 @@ public class BgDataModel {
      */
     public final ArrayList<AppInfo> cachedPredictedItems = new ArrayList<>();
 
-    /**
-     * @see Callbacks#FLAG_HAS_SHORTCUT_PERMISSION
-     * @see Callbacks#FLAG_QUIET_MODE_ENABLED
-     * @see Callbacks#FLAG_QUIET_MODE_CHANGE_PERMISSION
-     */
-    public int flags;
-
     /**
      * Maps all launcher activities to counts of their shortcuts.
      */