Merge "Don't crash when there is no rollback dir" into main

     */

    private static List<Rollback> loadRollbacks(File rollbackDataDir) {

        List<Rollback> rollbacks = new ArrayList<>();

        rollbackDataDir.mkdirs();

        for (File rollbackDir : rollbackDataDir.listFiles()) {

        File[] rollbackDirs = rollbackDataDir.listFiles();

        if (rollbackDirs == null) {

            Slog.e(TAG, "Folder doesn't exist: " + rollbackDataDir);

            return rollbacks;

        }

        for (File rollbackDir : rollbackDirs) {

            if (rollbackDir.isDirectory()) {

                try {

                    rollbacks.add(loadRollback(rollbackDir));