[Android] Firebase FCM을 사용하여 서버 없이 push 알림 구현하기 code3.java

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