Fix manifest warnings

app/src/amazon/java/org/tasks/location/GeofenceTransitionsIntentService.java

@@ -1,3 +1,22 @@
 package org.tasks.location;
 
-public class GeofenceTransitionsIntentService {}
+import android.app.IntentService;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import androidx.annotation.Nullable;
+
+public class GeofenceTransitionsIntentService extends IntentService {
+
+  public GeofenceTransitionsIntentService() {
+    super("GeofenceTransitionsIntentService");
+  }
+
+  @Override
+  protected void onHandleIntent(@Nullable Intent intent) {}
+
+  public static class Broadcast extends BroadcastReceiver {
+    @Override
+    public void onReceive(Context context, Intent intent) {}
+  }
+}

app/src/generic/java/org/tasks/location/GeofenceTransitionsIntentService.java

@@ -1,3 +1,22 @@
 package org.tasks.location;
 
-public class GeofenceTransitionsIntentService {}
+import android.app.IntentService;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import androidx.annotation.Nullable;
+
+public class GeofenceTransitionsIntentService extends IntentService {
+
+  public GeofenceTransitionsIntentService() {
+    super("GeofenceTransitionsIntentService");
+  }
+
+  @Override
+  protected void onHandleIntent(@Nullable Intent intent) {}
+
+  public static class Broadcast extends BroadcastReceiver {
+    @Override
+    public void onReceive(Context context, Intent intent) {}
+  }
+}