Write file with WWW on Android

The code below works well on PC, however, not on Android. The app already has a file at the "androidPath", and even after www, file never changed. What am I missing here?

 using UnityEngine;
 using System.Collections;
 using System.IO;
 
 public class Downloader : MonoBehaviour {
 
     string url = "http://SOMEDOMAIN.com/_inc/_sqlite/nexco.db3";
 
     // Use this for initialization
     void Start () {
         // test method to dawnload png file.
         sendGetRequest();
     }
     
     // Update is called once per frame
     void Update () {
     }
 
     private IEnumerator TestDownload(WWW www){
         //yield return www;
         // already method has got the WWW
         while (!www.isDone) {
             Debug.Log("downloaded " + (www.progress*100.0).ToString() + "%...");
             yield return null;
         }
 
         // set path to download item.
         if (www.isDone) {
             #if UNITY_EDITOR
             string editorPath = Application.dataPath + "/StreamingAssets/nexco.db3";
             // first, delete file..
             File.Delete(editorPath);
             File.WriteAllBytes(editorPath, www.bytes);
 
             #elif UNITY_ANDROID
             string DatabaseName = "nexco.db3";
             var filepath = string.Format("{0}/{1}", Application.persistentDataPath, DatabaseName);
             string androidPath = "jar:file://" + Application.dataPath + "!/assets/" + DatabaseName;
             // first delete file
             File.Delete(androidPath);
             File.WriteAllBytes(androidPath, www.bytes);
             #endif            
         }
 
         Debug.Log("download done!");
     }
 
     /*
      * www thing
      * methods to handle with data
      */
     void sendGetRequest(){
         WWWForm form = new WWWForm ();
         form.AddField ("Username", "SOMEUSER");
         form.AddField ("Password", "SOMEPASS");
 
         var headers = form.headers;
         //var rawData = form.data;
         string secretKey = "SOMEUSER" + ":" + "SOMEPASS";
         headers["Authorization"]="Basic " + System.Convert.ToBase64String(
             System.Text.Encoding.ASCII.GetBytes(secretKey));
   
   
         // in case request is GET not POST, the second parameter could be null.
         WWW www = new WWW(url, null, headers);
         //yield
         StartCoroutine(TestDownload(www));
     }
 }