Adding support for dynamically change icon shape for AdaptiveIcons

> This would allow developers to verify their icon designs on different
device configurations
> This settings is only visible when developer settings is enabled

Change-Id: I7e32abfede001c134f23390734dcd39c93b68b9a

src/com/android/launcher3/util/SQLiteCacheHelper.java

@@ -83,6 +83,10 @@ public abstract class SQLiteCacheHelper {
                 mTableName, columns, selection, selectionArgs, null, null, null);
     }
 
+    public void clear() {
+        mOpenHelper.clearDB(mOpenHelper.getWritableDatabase());
+    }
+
     protected abstract void onCreateTable(SQLiteDatabase db);
 
     /**