Fix generic build

src/generic/java/com/todoroo/astrid/gtasks/sync/GtasksSyncV2Provider.java

@@ -23,4 +23,8 @@ public class GtasksSyncV2Provider {
     public void synchronizeList(GtasksList list, SyncResultCallback callback) {
 
     }
+
+    public void clearCompleted(GtasksList list, SyncResultCallback callback) {
+
+    }
 }