Migrate app update checker to AndroidX Work

app/build.gradle

@@ -220,6 +220,7 @@ dependencies {
     // https://developer.android.com/jetpack/androidx/releases/viewpager2#1.1.0-alpha01
     implementation 'androidx.viewpager2:viewpager2:1.1.0-beta01'
     implementation 'androidx.webkit:webkit:1.4.0'
+    implementation 'androidx.work:work-runtime:2.7.1'
     implementation 'com.google.android.material:material:1.4.0'
 
 /** Third-party libraries **/

app/src/main/AndroidManifest.xml

@@ -381,9 +381,6 @@
         <service
             android:name=".RouterActivity$FetcherService"
             android:exported="false" />
-        <service
-            android:name=".CheckForNewAppVersion"
-            android:exported="false" />
 
         <!-- opting out of sending metrics to Google in Android System WebView -->
         <meta-data android:name="android.webkit.WebView.MetricsOptOut" android:value="true" />

app/src/main/java/org/schabi/newpipe/MainActivity.java

@@ -20,7 +20,6 @@
 
 package org.schabi.newpipe;
 
-import static org.schabi.newpipe.CheckForNewAppVersion.startNewVersionCheckService;
 import static org.schabi.newpipe.util.Localization.assureCorrectAppLanguage;
 
 import android.content.BroadcastReceiver;
@@ -174,10 +173,9 @@ protected void onPostCreate(final Bundle savedInstanceState) {
         final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(app);
 
         if (prefs.getBoolean(app.getString(R.string.update_app_key), true)) {
-            // Start the service which is checking all conditions
+            // Start the worker which is checking all conditions
             // and eventually searching for a new version.
-            // The service searching for a new NewPipe version must not be started in background.
-            startNewVersionCheckService();
+            NewVersionWorker.enqueueNewVersionCheckingWork(app);
         }
     }