Add support for building apk in release

content/shell/android/java/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.
  -->
 
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="org.chromium.content_shell">
 
     <permission android:name="org.chromium.content_shell.permission.SANDBOX"
             android:protectionLevel="signature" />
 
     <application android:name="ContentShellApplication"
-            android:label="ContentShell"
-            android:debuggable="true">
+            android:label="ContentShell">
         <activity android:name="ContentShellActivity"
                   android:launchMode="singleTask"
                   android:theme="@android:style/Theme.Holo.Light.NoActionBar"
                   android:configChanges="orientation|keyboardHidden|keyboard|screenSize"
                   android:hardwareAccelerated="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN"/>
                 <category android:name="android.intent.category.LAUNCHER"/>
             </intent-filter>
         </activity>
@@ skipping 28 matching lines @@
                  android:permission="org.chromium.content_shell.permission.SANDBOX"
                  android:exported="false" />
     </application>
 
     <uses-sdk android:minSdkVersion="14" android:targetSdkVersion="14" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.VIBRATE"/>
     <uses-permission android:name="android.permission.WAKE_LOCK"/>
 </manifest>