[TIMOB-15680] iOS: Need to expose the NSTextEffectLetterpressStyle constant for AttributedString

   var win = Ti.UI.createWindow({
       backgroundColor: '#ddd',
   });
    
   win.open();
    
   var text =  'Bacon ipsum dolor sit amet fatback leberkas salami sausage tongue strip steak. Andouille drumstick meatball boudin shank flank sausage, ribeye ham venison doner bacon ham hock. Appcelerator Titanium sucks rocks! Filet mignon ham pancetta, tail salami pork chop short ribs leberkas kielbasa t-bone tri-tip bresaola. Kevin beef ribs tail hamburger andouille filet mignon bresaola ham ham hock flank meatball pork chop corned beef';
    
   var attr = Ti.UI.iOS.createAttributedString({
       text: text,
       attributes: [
           {
           	type: Ti.UI.iOS.ATTRIBUTE_TEXT_EFFECT,
           	value: Ti.UI.iOS.ATTRIBUTE_LETTERPRESS_STYLE,
   		range: [0, text.length]
           }
       ]
   });
    
   var label = Ti.UI.createLabel({
       left: 20,
       right: 20,
       height: Ti.UI.SIZE,
       backgroundColor: 'red',
       color: '#ccc',
       attributedString: attr
   });
    
   win.add(label);