Request permission for Custom Permission

Question

I learned to define my own custom permission with different level (normal, signature, dangerous) a few hours ago. Then I followed the android documentation and this question's answered by Yury to test it in real. First I made the permission level normal and after clicking button from first activity, I can access the second activity. But when I set it dangerous, I failed to access the second activity. I got Security exception - permission denial everytime. Then I go to 'Permission' section in the app settings and see my custom permission is turned off. I turn it on and then can access the activity.
But my question is how I can request this permission like other dangerous permission defined by android system and show dialog and grant it without going to the permission section in app settings. I know how to access permission with -

if (ContextCompat.checkSelfPermission(thisActivity,
        Manifest.permission.READ_CONTACTS)
        != PackageManager.PERMISSION_GRANTED) {

    // Permission is not granted
    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
            Manifest.permission.READ_CONTACTS)) {
        // Show an explanation to the user *asynchronously* -- don't block
        // this thread waiting for the user's response! After the user
        // sees the explanation, try again to request the permission.
    } else {
        // No explanation needed; request the permission
        ActivityCompat.requestPermissions(thisActivity,
                new String[]{Manifest.permission.READ_CONTACTS},
                MY_PERMISSIONS_REQUEST_READ_CONTACTS);

        // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
        // app-defined int constant. The callback method gets the
        // result of the request.
    }
} else {
    // Permission has already been granted
}

But the problem is android's default permissions are defined in Manifest.permission.READ_CONTACTS but how I define my custom permission with that. My code is given below.
PermissionTestServerActivity (First activity):-

public class PermissionTestServerActivity extends Activity {
    private static final String TAG = "PermissionTestServerActivity";

    /** Called when the activity is first created. */
    Button btnTest;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        btnTest = (Button) findViewById(R.id.btnTest);
        btnTest.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Log.d(TAG, "Button pressed!");
                Intent in = new Intent();
                in.setAction("com.testpackage.permissiontestclient.MyAction");
                in.addCategory("android.intent.category.DEFAULT");
                startActivity(in);
            }
        });
    }
}

And its manifest :-

<?xml version="1.0" encoding="utf-8"?>
<uses-sdk android:minSdkVersion="10" />
<uses-permission android:name="com.testpackage.mypermission"/>

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >
    <activity
        android:name=".PermissionTestServerActivity"
        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>

PermissionTestClient's manifest (Second activity):-

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

    <uses-sdk android:minSdkVersion="10" />
    <permission android:name="com.testpackage.mypermission" android:label="my_permission" android:protectionLevel="dangerous"></permission>

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:permission="com.testpackage.mypermission"
            android:name=".PermissionTestClientActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

            <intent-filter >
                <action android:name="com.testpackage.permissiontestclient.MyAction" />
                <category android:name="android.intent.category.DEFAULT" />                
            </intent-filter>
        </activity>
    </application>

</manifest>