Create a new C# script in Unity and replace it's contents with the following
using UnityEngine;
using System.Collections;
public static class UnityAndroidPlugin {
}
Create a new Java class in Android Studio and replace it's contents with the following
package com.axs.unityandroidplugin;
import android.util.Log;
import android.widget.Toast;
import android.app.ActivityManager;
import android.content.Context;
public class UnityAndroidNative {
}
...
Create a new C# script in Unity and paste these contents
using UnityEngine;
using System.Collections;
public class UnityAndroidPluginGUI : MonoBehaviour {
void OnGUI () {
}
}