BurningDroid

const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
var db = admin.firestore();

exports.myUpdateTrigger = functions.firestore
    .document('recruits/{recruitId}')
    .onUpdate(event => {

        ...

BurningDroid

exports.myUpdateTrigger = functions.firestore
    .document('recruits/{recruitId}')
    .onUpdate(event => {

        ...

});

BurningDroid

public class FCMService extends FirebaseMessagingService {

    public FCMService() {
    }

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);

        if (remoteMessage.getData().size() > 0) {

BurningDroid

<meta-data
    android:name="com.google.firebase.messaging.default_notification_icon"
    android:resource="@drawable/ic_user_add" />
<meta-data
    android:name="com.google.firebase.messaging.default_notification_color"
    android:resource="@color/colorAccent" />

...

<service android:name=".service.fcm.FCMService">

BurningDroid

public class FCMInstanceIdService extends FirebaseInstanceIdService {

    @Override
    public void onTokenRefresh() {
        String refreshedToken = FirebaseInstanceId.getInstance().getToken();
        ...
    }
}

BurningDroid

<service android:name=".service.fcm.FCMInstanceIdService">
    <intent-filter>
        <action android:name="com.google.firebase.INSTANCE_ID_EVENT" />
    </intent-filter>
</service>

BurningDroid

public void onSaveInstanceState(Bundle outState);
public void onViewStateRestored(@Nullable Bundle savedInstanceState);

BurningDroid

@Override
public void onViewStateRestored(@Nullable Bundle savedInstanceState) {
    super.onViewStateRestored(savedInstanceState);
    if (savedInstanceState != null) {
        mLayoutManagerSavedState = savedInstanceState.getParcelable("key");
    }
}

@Override
public void onStart() {

BurningDroid

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putParcelable("key", mRecyclerView.getLayoutManager().onSaveInstanceState());
}

BurningDroid

boolean commit();
void apply();