Contextual custom card cannot dismiss - android wear - wear-os

Question

Android wear app for Custom notification.By a button click it will notify.But its just showing only a black screen inside card frame,also can't dismiss by left to right swipe.Do i need to add any additional codes to make the card dismissal.
MainActivity
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final WatchViewStub stub = (WatchViewStub) findViewById(R.id.watch_view_stub);
stub.setOnLayoutInflatedListener(new WatchViewStub.OnLayoutInflatedListener() {
#Override
public void onLayoutInflated(WatchViewStub stub) {
speakButton= (Button) findViewById(R.id.speakButton);
speakButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
postNotif();
}
});
}
});
}
private void postNotif(){
int notificationId=001;
Intent notificationIntent = new Intent(this, NotificationActivity.class);
PendingIntent notificationPendingIntent = PendingIntent.getActivity(this, 0,notificationIntent,PendingIntent.FLAG_UPDATE_CURRENT);
Notification.Builder notificationBuilder =
new Notification.Builder(this)
.setOngoing(true)
.setSmallIcon(R.drawable.ic_launcher)
.extend(new Notification.WearableExtender()
.setStartScrollBottom(false)
.setHintHideIcon(true)
.setDisplayIntent(notificationPendingIntent));
NotificationManager notificationManager= (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
notificationManager.notify(notificationId,notificationBuilder.build());
}
NotificationActivity.class
public class NotificationActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search_result_card);
}
}
search_result_card.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.wearable.view.BoxInsetLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_height="match_parent"
android:background="#00ffffff"
android:id="#+id/fragment_container"
android:layout_width="match_parent">
<android.support.wearable.view.CardScrollView
android:id="#+id/card_scroll_view"
android:layout_height="match_parent"
android:layout_width="match_parent">
<android.support.wearable.view.CardFrame
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_gravity="bottom"
android:id="#+id/card_frame"
android:alpha=".9">
<TextView
android:layout_height="match_parent"
android:layout_width="fill_parent"
android:text="Bnp Paribas"
android:textColor="#color/black"
android:textSize="18sp"
android:id="#+id/security_label"
android:alpha=".7" />
<TextView
android:fontFamily="sans-serif-light"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:layout_width="wrap_content"
android:text="45.99"
android:id="#+id/security_rate"
android:textColor="#color/black"
android:textSize="16sp"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:orientation="horizontal">
<TextView
android:fontFamily="sans-serif-light"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="▲ +1,21%"
android:textColor="#color/black"
android:layout_gravity="left|bottom"
android:textSize="14sp"
android:id="#+id/performance_percent"/>
<TextView
android:fontFamily="sans-serif-light"
android:layout_height="wrap_content"
android:layout_width="56dp"
android:text="+1,76 €"
android:id="#+id/perf_value"
android:textColor="#color/black"
android:layout_marginLeft="15dp"
android:textSize="14sp"
android:layout_gravity="right|bottom" />
</LinearLayout>
</android.support.wearable.view.CardFrame>
</android.support.wearable.view.CardScrollView>
</android.support.wearable.view.BoxInsetLayout>
AndroidManifest.xml
<activity android:name=".NotificationActivity"
android:exported="true"
android:allowEmbedded="true"
android:taskAffinity=""
android:theme="#android:style/Theme.DeviceDefault.Light" />