Implement push notifications

app/src/google/AndroidManifest.xml

@@ -1,16 +1,27 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest
     xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools">
+    xmlns:tools="http://schemas.android.com/tools"
+    package="org.traccar.manager">
 
     <application
-        android:name="org.traccar.client.GoogleMainApplication"
+        android:name=".GoogleMainApplication"
         tools:replace="android:name">
 
         <meta-data
             android:name="google_analytics_adid_collection_enabled"
             android:value="false" />
 
+        <meta-data
+            android:name="com.google.firebase.messaging.default_notification_channel_id"
+            android:value="@string/notification_channel_id" />
+
+        <service android:name=".ManagerMessagingService">
+            <intent-filter>
+                <action android:name="com.google.firebase.MESSAGING_EVENT" />
+            </intent-filter>
+        </service>
+
     </application>
 
 </manifest>