Add DartPackage annotation to all mojo_services mojoms

mojo/services/prediction/public/interfaces/prediction.mojom

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+[DartPackage="mojo_services"]
 module prediction;
 
 struct Settings {
   bool correction_enabled;
   bool block_potentially_offensive;
   bool space_aware_gesture_enabled;
 };
 
 struct PredictionInfo {
   array<string> previous_words;
   string current_word;
 };
 
 interface PredictionService {
   SetSettings(Settings settings);
 
   GetPredictionList(PredictionInfo prediction_info) => (array<string>? prediction_list);
 };