Facebook Messenger Android app integration

Question

I am trying to integrate Facebook Messenger platform in my Android app.

FacebookSdk.sdkInitialize(getApplicationContext());
String mimeType = "image/jpeg";
String metadata = "{ \"type\": \"event\" }";
ShareToMessengerParams shareToMessengerParams = ShareToMessengerParams
    .newBuilder(Uri.fromFile(new File("/sdcard/Images/img.jpg")), mimeType)
    .setMetaData(metadata)
    .build();
MessengerUtils.shareToMessenger(this, 1, shareToMessengerParams);

Content from AndroidManifest.xml

<intent-filter>
    <action android:name="android.intent.action.PICK"/>
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="com.facebook.orca.category.PLATFORM_THREAD_20150314" />
</intent-filter>

Then I am using below code to get metadata back from Intent

MessengerThreadParams mThreadParams = MessengerUtils.getMessengerThreadParamsForIntent(intent);
String metadata = mThreadParams.metadata;

But still I am not getting metadata back, I followed it exactly the way its mentioned in Messenger Documentation.