fcm token is refreshed forcily

fcm_token_refresh.java

Completable.fromCallable(() -> {
    try {
        FirebaseInstanceId.getInstance().deleteInstanceId();
        PushTokenRepository.getInstance().deleteGcmToken();
        FirebaseInstanceId.getInstance().getToken();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return Completable.complete();
}).subscribeOn(Schedulers.newThread())
        .subscribe();