move backgroundFetch() to FetchForegroundService

src/gplay/java/org/thoughtcrime/securesms/notifications/FcmReceiveService.java

@@ -97,14 +97,6 @@ public static String getToken() {
   public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
     Log.i(TAG, "FCM push notification received");
     FetchForegroundService.start(this);
-
-    // we should complete within 20 seconds,
-    // see https://firebase.google.com/docs/cloud-messaging/android/receive
-    if (!ApplicationContext.dcAccounts.backgroundFetch(19)) {
-      FetchForegroundService.stop(this);
-    }
-
-    Log.i(TAG, "background fetch done");
   }
 
   @Override

src/main/java/org/thoughtcrime/securesms/service/FetchForegroundService.java

@@ -5,15 +5,20 @@
 import android.content.Context;
 import android.content.Intent;
 import android.os.IBinder;
+import android.util.Log;
 
 import androidx.annotation.Nullable;
 import androidx.core.app.NotificationCompat;
 import androidx.core.content.ContextCompat;
 
+import org.thoughtcrime.securesms.ApplicationContext;
 import org.thoughtcrime.securesms.R;
+import org.thoughtcrime.securesms.notifications.FcmReceiveService;
 import org.thoughtcrime.securesms.notifications.NotificationCenter;
+import org.thoughtcrime.securesms.util.Util;
 
 public final class FetchForegroundService extends Service {
+  private static final String TAG = FcmReceiveService.class.getSimpleName();
   private static final Object SERVICE_LOCK = new Object();
   private static Intent service;
 
@@ -38,6 +43,7 @@ public static void stop(Context context) {
 
   @Override
   public void onCreate() {
+    Log.i(TAG, "Creating fetch service");
     super.onCreate();
 
     Notification notification = new NotificationCompat.Builder(this, NotificationCenter.CH_GENERIC)
@@ -46,6 +52,18 @@ public void onCreate() {
       .build();
 
     startForeground(NotificationCenter.ID_FETCH, notification);
+
+    // Start explicit fetch only after we marked ourselves as requiring foreground;
+    // this may help we on getting network and time adequately
+    // Fetch is started in background to not block the UI.
+    // We then run not longer than the max. of 20 seconds,
+    // see https://firebase.google.com/docs/cloud-messaging/android/receive .
+    Util.runOnAnyBackgroundThread(() -> {
+      Log.i(TAG, "Starting fetch");
+      if (!ApplicationContext.dcAccounts.backgroundFetch(19)) {
+        FetchForegroundService.stop(this);
+      }
+    });
   }
 
   @Override