Instead of adding an action, define your own notification layout and connect a pendingIntent to fire to that via RemoteView.
(The example below is based on the Holo look and feel and would still need to updated for lollipop. You can find all te correct resources in the android-21/data/res folder of your sdk)
// NOTE: while creating pendingIntent: requestcode must be different!
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(myService)
.setSmallIcon(R.drawable.notification_icon).setContentTitle("My Title")
.setContentText("Service running in the background");
Intent openIntent = new Intent(MainActivity.this, MainActivity.class);
PendingIntent pOpenIntent = PendingIntent.getActivity(this, 0, openIntent, 0);
mBuilder.setContentIntent(pOpenIntent);
// Notification with exit button if supported
String ACTION_NOTIFICATION_EXITACTIVITY = "com.jmols.example.exitactivity";
Intent exitIntent = new Intent();
exitIntent.setAction(ACTION_NOTIFICATION_EXITACTIVITY);
PendingIntent pExitIntent = PendingIntent.getBroadcast(this, 1, exitIntent, 0);
RemoteViews view = new RemoteViews(getPackageName(), R.layout.notification_discoveryservice);
view.setOnClickPendingIntent(R.id.notification_closebtn_ib, pExitIntent);
mBuilder.setContent(view);
With a notification layout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:internal="http://schemas.android.com/apk/prv/res/android"
android:id="@+id/status_bar_latest_event_content"
android:layout_width="match_parent"
android:layout_height="64dp"
internal:layout_maxHeight="64dp"
internal:layout_minHeight="64dp" >
<ImageView
android:id="@+id/notification_icon_iv"
android:layout_width="64dp"
android:layout_height="64dp"
android:padding="10dp"
android:layout_alignParentLeft="true"
android:scaleType="center"
android:src="@drawable/notification_icon"
android:background="#3333B5E5" />
<ImageButton
android:id="@+id/notification_closebtn_ib"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:scaleType="centerInside"
android:src="@drawable/notification_exitbtn"
android:background="@drawable/notification_imagebtn_bg"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="fill_vertical"
android:gravity="top"
android:minHeight="64dp"
android:layout_toRightOf="@id/notification_icon_iv"
android:layout_toLeftOf="@id/notification_closebtn_ib"
android:orientation="vertical"
android:paddingBottom="2dp"
android:paddingEnd="8dp"
android:paddingTop="2dp" >
<TextView
android:id="@+id/notification_title_tv"
style="@android:style/TextAppearance.StatusBar.EventContent.Title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:ellipsize="marquee"
android:paddingTop="6dp"
android:singleLine="true"
android:text="JMols Service" />
<TextView
android:id="@+id/notification_contenttext_tv"
style="@android:style/TextAppearance.StatusBar.EventContent"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:ellipsize="marquee"
android:singleLine="true"
android:text="Service running in the background" />
</LinearLayout>
</RelativeLayout>
And the notification background is:
<selector xmlns:android="http://schemas.android.com/apk/res/android"
android:exitFadeDuration="@android:integer/config_mediumAnimTime">
<item android:state_pressed="true" android:drawable="@drawable/notification_bg_normal_pressed" />
<item android:state_pressed="false" android:drawable="@drawable/notification_bg_normal" />
</selector>

And the notification imagebutton background is:
<selector xmlns:android="http://schemas.android.com/apk/res/android"
android:exitFadeDuration="@android:integer/config_mediumAnimTime">
<item android:state_pressed="true" android:drawable="@drawable/notification_imagebtn_bg_normal_pressed" />
<item android:state_pressed="false" android:drawable="@drawable/notification_imagebtn_bg_normal" />
</selector>
