Android Default Overflow icon was not displaying in action bar

Question

In my project i want to display overflow icon in action bar. I tried with below code but instead of action bar it is displaying on menu button click. I tried it in many ways but not succeeded.Please help me to get this done.

And also i tried with this stack link

Thanks in Advance.

Menu.xml:-

<item
    android:id="@+id/action_search"
    android:icon="@drawable/ic_action_search"
    android:showAsAction="never"
    android:title="@string/action_search"/>

<!-- Location Found -->
<item
    android:id="@+id/action_location_found"
    android:icon="@drawable/ic_action_locate"
    android:showAsAction="never"
    android:title="Location"/>

<!-- Refresh -->
<item
    android:id="@+id/action_refresh"
    android:icon="@drawable/ic_action_refresh"
    android:showAsAction="never"
    android:title="Refresh"/>

<!-- Help -->
<item
    android:id="@+id/action_help"
    android:icon="@drawable/ic_action_help"
    android:showAsAction="never"
    android:title="Help"/>

<!-- Check updates -->
<item
    android:id="@+id/action_check_updates"
    android:icon="@drawable/ic_action_refresh"
    android:showAsAction="never"
    android:title="Updates"/>

MainActivity.java:-

    package com.example.actionbar;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.main_activity_bar, menu);
        return super.onCreateOptionsMenu(menu);
    }

    /**
     * On selecting action bar icons
     * */
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Take appropriate action for each action item click
        switch (item.getItemId()) {
         case R.id.action_search:
         // search action
         return true;
         case R.id.action_location_found:
         // location found

         return true;
         case R.id.action_refresh:
         // refresh
         return true;
         case R.id.action_help:
         // help action
         return true;
         case R.id.action_check_updates:
         // check for updates action
         return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }
}

Manifest.xml:-

   <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.actionbar"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>