Remove redundant field initialization in Java code.

components/policy/android/java/src/org/chromium/policy/AbstractAppRestrictionsProvider.java

 // 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.
 
 package org.chromium.policy;
 
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.StrictMode;
 
 import org.chromium.base.Log;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 
 /**
  * Retrieves app restrictions and provides them to the parent class as Bundles.
  *
  * Needs to be subclassed to specify how to retrieve the restrictions.
  */
 public abstract class AbstractAppRestrictionsProvider extends PolicyProvider {
     private static final String TAG = "policy";
 
     /** {@link Bundle} holding the restrictions to be used during tests. */
-    private static Bundle sTestRestrictions = null;
+    private static Bundle sTestRestrictions;
 
     private final Context mContext;
     private final BroadcastReceiver mAppRestrictionsChangedReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
             refresh();
         }
     };
 
     /**
@@ skipping 83 matching lines @@
      * restrictions to an empty bundle if nothing is specified. To stop using a test bundle,
      * provide {@code null} as value instead.
      */
     @VisibleForTesting
     public static void setTestRestrictions(Bundle policies) {
         Log.d(TAG, "Test Restrictions: %s",
                 (policies == null ? null : policies.keySet().toArray()));
         sTestRestrictions = policies;
     }
 }