Adding some widget addition flow tests

> Added two dummy widget providers: with config and without config
> Added tests for verify widget config flow

Change-Id: I4577f085abe8f8b82047b644c71cc9065358153a
diff --git a/src/com/android/launcher3/LauncherAppWidgetInfo.java b/src/com/android/launcher3/LauncherAppWidgetInfo.java
index 285a93c..1e0f285 100644
--- a/src/com/android/launcher3/LauncherAppWidgetInfo.java
+++ b/src/com/android/launcher3/LauncherAppWidgetInfo.java
@@ -65,7 +65,7 @@
     /**
      * Indicates that the widget hasn't been instantiated yet.
      */
-    static final int NO_ID = -1;
+    public static final int NO_ID = -1;
 
     /**
      * Indicates that this is a locally defined widget and hence has no system allocated id.
@@ -126,7 +126,7 @@
     }
 
     @Override
-    void onAddToDatabase(ContentWriter writer) {
+    public void onAddToDatabase(ContentWriter writer) {
         super.onAddToDatabase(writer);
         writer.put(LauncherSettings.Favorites.APPWIDGET_ID, appWidgetId)
                 .put(LauncherSettings.Favorites.APPWIDGET_PROVIDER, providerName.flattenToString())