Firebase Remote Config - cannot find symbol

Trying to build the android app in android studio.

but i get this 2 error, and dont now how to fix them..

app\src\main\java\com\xxxxxx\user\UserApplication.java:62: error: cannot find symbol
firebaseRemoteConfig.setDefaults(remoteConfigDefaults);
                            ^
symbol:   method setDefaults(Map<String,Object>)
location: variable firebaseRemoteConfig of type FirebaseRemoteConfig

app\src\main\java\com\xxxxxxx\user\UserApplication.java:69: error: cannot find symbol
firebaseRemoteConfig.activateFetched();
                                                ^
symbol:   method activateFetched()
location: variable firebaseRemoteConfig of type FirebaseRemoteConfig

I hope someone kind soul can help me.

My code in UserApplication.java

public void onCreate() {
        super.onCreate();
        mInstance = this;
        //initCalligraphyConfig();


        final FirebaseRemoteConfig firebaseRemoteConfig = FirebaseRemoteConfig.getInstance();

        // set in-app defaults
        Map<String, Object> remoteConfigDefaults = new HashMap();
        remoteConfigDefaults.put(ForceUpdateChecker.KEY_UPDATE_REQUIRED, false);
        remoteConfigDefaults.put(ForceUpdateChecker.KEY_CURRENT_VERSION, "1.0");
        remoteConfigDefaults.put(ForceUpdateChecker.KEY_UPDATE_URL,
                "https://play.google.com/store/apps/details?id="+getPackageName());

        firebaseRemoteConfig.setDefaults(remoteConfigDefaults);
        firebaseRemoteConfig.fetch(10) // fetch every minutes
                .addOnCompleteListener(new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        if (task.isSuccessful()) {
                            Log.d(TAG, "remote config is fetched.");
                            firebaseRemoteConfig.activateFetched();
                        }
                    }
                });
    }