Refactor cronet library loader. Move java LibraryLoader into cronet.jar.

components/cronet/android/java/src/org/chromium/net/LibraryLoader.java

 // Copyright 2014 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 org.chromium.cronet_sample_apk;
+package org.chromium.net;
 
 import android.util.Log;
 
 /**
  * Cronet Library Loader.
  */
 public class LibraryLoader {
     private static final String TAG = "LibraryLoader";
 
     private static Boolean sInitialized = false;
 
     public static void ensureInitialized() throws UnsatisfiedLinkError {
         if (sInitialized)
             return;
         sInitialized = true;
         System.loadLibrary("cronet");
         Log.i(TAG, "libcronet initialization success.");
     }
 }