Issue 4260 - Replace Apache Commons Lang classes

src/org/adblockplus/android/AdvancedPreferences.java

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 package org.adblockplus.android;
 
 import java.util.ArrayList;
 import java.util.List;
 
 import org.adblockplus.android.compat.ProxyProperties;
 import org.adblockplus.android.configurators.IptablesProxyConfigurator;
-import org.apache.commons.lang.StringUtils;
+import org.adblockplus.android.StringUtils;
 
 import android.app.AlertDialog;
 import android.app.Dialog;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Build;
 import android.os.Bundle;
 import android.preference.Preference;
 import android.preference.Preference.OnPreferenceClickListener;
@@ skipping 213 matching lines @@
               {
                 dialog.cancel();
               }
             });
         dialog = builder.create();
         break;
     }
     return dialog;
   }
 }