fix(android): enable push notifications in background/killed state

frontend/android/app/src/main/AndroidManifest.xml

@@ -18,15 +18,30 @@
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC"/>
+    <uses-permission android:name="android.permission.SCHEDULE_EXACT_ALARM"/>
     <application
         android:usesCleartextTraffic="true"
         android:label="TIS RMS"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher">
+        <meta-data
+            android:name="com.pravera.flutter_foreground_task.notification_icon"
+            android:resource="@mipmap/ic_launcher" />
         <service
             android:name="com.pravera.flutter_foreground_task.service.ForegroundService"
             android:foregroundServiceType="dataSync"
+            android:exported="false"
             android:stopWithTask="false"/>
+        <receiver
+            android:name=".BootReceiver"
+            android:exported="true"
+            android:enabled="true">
+            <intent-filter>
+                <action android:name="android.intent.action.BOOT_COMPLETED"/>
+                <action android:name="android.intent.action.QUICKBOOT_POWERON"/>
+                <category android:name="android.intent.category.DEFAULT"/>
+            </intent-filter>
+        </receiver>
         <activity
             android:name=".SplashActivity"
             android:exported="true"

frontend/lib/main.dart

@@ -78,7 +78,7 @@ void main() async {
       "background_sync_task",
       frequency: const Duration(minutes: 15),
       constraints: Constraints(networkType: NetworkType.connected),
-      existingWorkPolicy: ExistingPeriodicWorkPolicy.keep,
+      existingWorkPolicy: ExistingPeriodicWorkPolicy.update,
     );
   }