Add smartspace as a widget to first page (implementation 2)

Flag: SMARTSPACE_AS_A_WIDGET
Test: verify that the smartspace gets replaced with a smartspace widget
Bug: 300140279
Change-Id: I42c170de5e2a9fd3d24d99bb8b09cf412c55e3a5

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

@@ -171,6 +171,11 @@ public abstract class BaseLauncherBinder {
      */
     public abstract void bindWidgets();
 
+    /**
+     * bindWidgets is abstract because it is a no-op for the go launcher.
+     */
+    public abstract void bindSmartspaceWidget();
+
     /**
      * Sorts the set of items by hotseat, workspace (spatially from top to bottom, left to right)
      */