How can I send a kml file to Google Earth, like MyTracks (open source) do?

I don't know if you have seen the amazing Mytrack update, but it allow to send a kml file to Google Earth app and display it inside the Google app (if installed, of course).

The source code is there: http://code.google.com/p/mytracks/source/browse/

but I cannot find the way to achieve such a thing.

I think I found something here: http://code.google.com/r/jshih-mytracks3/source/browse/MyTracks/src/com/google/android/apps/mytracks/io/file/SaveActivity.java?spec=svn5178eb75934b7f0c4c23ec26b7d79a0787de18b8&r=5178eb75934b7f0c4c23ec26b7d79a0787de18b8

else if (playTrack) {
        Intent intent = new Intent()
            .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK)
            .putExtra(GOOGLE_EARTH_TOUR_FEATURE_ID, KmlTrackWriter.TOUR_FEATURE_ID)
            .setClassName(GOOGLE_EARTH_PACKAGE, GOOGLE_EARTH_CLASS)
            .setDataAndType(Uri.fromFile(new File(savedPath)), GOOGLE_EARTH_KML_MIME_TYPE);
        startActivity(intent);

The hardcoded way gives this code:

    Intent intent = new Intent()
            .addFlags(
                    Intent.FLAG_ACTIVITY_CLEAR_TOP
                            | Intent.FLAG_ACTIVITY_NEW_TASK)
            .putExtra("com.google.earth.EXTRA.tour_feature_id","tour")
            .setClassName("com.google.earth", "com.google.earth.EarthActivity")
            .setDataAndType(Uri.fromFile(new File("/sdcard/test.kml")),
                    "application/vnd.google-earth.kml+xml");
    startActivity(intent);

But the above code simply displays the path with the same result than this code:

 Intent mapIntent = new Intent(Intent.ACTION_VIEW); 
    Uri uri1 = Uri.parse("file:///sdcard/test.kml"); 
    mapIntent.setData(uri1); 
    startActivity(Intent.createChooser(mapIntent, "Sample")); 

My objective is to get the same result, with a "play" button.