validate-recording-file

        Uri uri = Uri.fromFile(destination);
        MediaMetadataRetriever mmr = new MediaMetadataRetriever();
        mmr.setDataSource(WeNoteApplication.instance(), uri);
        String durationStr = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION);
        long length = 0L;
        try {
            length = Long.parseLong(durationStr);
        } catch (NumberFormatException e) {
            Log.e(TAG, "", e);
        }

        if (length <= 0L) {
            return null;
        }