code: public byte[] getTelemetryBytes(Beacon beacon) {
          if (beacon.getExtraDataFields().size() >= 5) {
              Beacon telemetryBeacon = new Beacon.Builder()
                      .setDataFields(beacon.getExtraDataFields())
                      .build();
              BeaconParser telemetryParser = new BeaconParser()
                      .setBeaconLayout(BeaconParser.EDDYSTONE_TLM_LAYOUT);
              byte[] telemetryBytes = telemetryParser.getBeaconAdvertisementData(telemetryBeacon);
              Log.d(TAG, "Rehydrated telemetry bytes are :" + byteArrayToString(telemetryBytes));
              return telemetryBytes;
          }
          else {
              return null;
          }
      }
docs: Extracts the raw Eddystone telemetry bytes from the extra data fields of an associated beacon.
  This is useful for passing the telemetry to Google's backend services.
  @param beacon
  @return the bytes of the telemetry frame