Revert "Revert "Revert "Revert "Changing GridMigrationTask to use ModelDbController directly""""

This reverts commit 3772b246c2.

Reason for revert: Fixed the test failure

Change-Id: Ibdc9e184fcb32c7caa4ab25d8753a46fa322b703

tests/src/com/android/launcher3/util/LauncherModelHelper.java

@@ -363,12 +363,6 @@ public class LauncherModelHelper {
         sandboxContext.getContentResolver().insert(contentUri, values);
     }
 
-    public void deleteItem(int itemId, @NonNull final String tableName) {
-        final Uri uri = Uri.parse("content://"
-                + LauncherProvider.AUTHORITY + "/" + tableName + "/" + itemId);
-        sandboxContext.getContentResolver().delete(uri, null, null);
-    }
-
     /**
      * Sets up a mock provider to load the provided layout by default, next time the layout loads
      */
@@ -426,7 +420,7 @@ public class LauncherModelHelper {
         }
 
         public SQLiteDatabase getDb() {
-            return getModelDbController().getDatabaseHelper().getWritableDatabase();
+            return getModelDbController().getDb();
         }
     }