Update targetSdkVersion for Chromium applications.

chrome/android/sync_shell/javatests/AndroidManifest.xml

 <?xml version="1.0" encoding="utf-8"?>
   <!-- Copyright (c) 2012 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. -->
   <!-- package name must be unique so suffix with "tests" so package loader
        doesn't ignore this. -->
   <manifest xmlns:android="http://schemas.android.com/apk/res/android"
       package="org.chromium.chrome.sync_shell.tests">
     <!-- We add an application tag here just so that we can indicate that this
          package needs to link against the android.test library, which is
          needed when building test cases. -->
     <application>
         <uses-library android:name="android.test.runner" />
         <activity android:name="org.chromium.sync.test.util.MockGrantCredentialsPermissionActivity"
             android:exported="false">
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
         </activity>
     </application>
-    <uses-sdk android:minSdkVersion="14" android:targetSdkVersion="20" />
+    <uses-sdk android:minSdkVersion="14" android:targetSdkVersion="21" />
     <instrumentation android:name="android.test.InstrumentationTestRunner"
         android:targetPackage="org.chromium.chrome.sync_shell"
         android:label="Tests for org.chromium.chrome.sync_shell"/>
     <uses-permission android:name="android.permission.RUN_INSTRUMENTATION" />
     <uses-permission android:name="android.permission.INJECT_EVENTS" />
     <uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
     <uses-permission android:name="android.permission.READ_LOGS"/>
     <uses-permission android:name="android.permission.WAKE_LOCK" />
 </manifest>