title: Get applicationContext from Unity 3d
body: <p>I am writing an android plugin for unity 3d, my problem is for initialize I need to pass applicationContext to a method. 
  So my <code>MyPlugin.cs</code> is like below</p>
  
  <pre><code>using UnityEngine;
  using System.Collections;
  
  public class MyPlugin : MonoBehaviour {
  
  void Awake () {
      Debug.Log ("awake");
      Initialize ();
  }
  
  public static void Initialize()
  {
      AndroidJavaClass playerClass = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
      AndroidJavaObject activity = playerClass.GetStatic&lt;AndroidJavaObject&gt;("currentActivity");
      AndroidJavaClass pluginClass = new AndroidJavaClass("com.mycompany.product.UnityPlugin");
      pluginClass.CallStatic("initialize", new object[1] {activity});
  }
  }
  </code></pre>
  
  <p>and in android <code>UnityPlugin.java</code> class I have</p>
  
  <pre><code>public class UnityPlugin extends Plugin {
      static public void initialize (Activity unityActivity){
          try {
             MyApp.initialize(unityActivity.getApplicationContext());
          } catch (NullPointerException e){
             Log.d("unity", "null pointer exception");
          }
      }
  }
  </code></pre>
  
  <p>and I get <code>NullPointerException</code> all the times. what is the correct way to get <code>AppilcationContext</code> from unity activities?</p>