code: private void onetimeDeviceSetup(Context context) {
          if (TextUtils.isEmpty(deviceDAO.device().getDeviceId())) {
              deviceDAO.setDeviceId(DeviceHelper.generateDeviceId(context));
              try {
                  deviceDAO.setInstanceId(FirebaseInstanceId.getInstance().getId());
              } catch (IllegalStateException e) {
                  deviceDAO.setInstanceId("empty");
              }
              deviceDAO.setAppVer(DeviceHelper.getAppVersion(context));
          }
      }
docs: Populates basic application/device data if app is running for the first time.