use KeyserverSyncWorker for updating keys in the foreground, too

OpenKeychain/src/main/res/menu/key_list.xml

@@ -37,6 +37,12 @@
         android:visible="false"
         app:showAsAction="never" />
 
+    <item
+        android:id="@+id/menu_key_list_debug_bgsync"
+        android:title="Debug / Background Key Sync"
+        android:visible="false"
+        app:showAsAction="never" />
+
     <item
         android:id="@+id/menu_key_list_debug_first_time"
         android:title="Debug / Show first time screen"