[TIMOB-18393] iOS7: No separator lines shown on option dialogs

Description

When an option dialog is displayed on an iOS7 iPad there are no separator lines between the rows, when compared to a iOS8 dialog it also appears to be sized differently.

Steps To Reproduce

1. Using the code below build to an iOS7 iPad, for comparison install to an iOS8 iPad too

var myWindow = Ti.UI.createWindow({
		height : Ti.UI.FILL,
		width : Ti.UI.FILL,
		backgroundColor : 'blue'
	});
 
	myWindow.open();
 
	var dialog = Ti.UI.createOptionDialog({
		cancel : -1,
		options : ["YES", "NO"],
		selectedIndex : 1,
		destructive : 1,
		title : "Option Dialog"
	});
	dialog.addEventListener('click', function(e) {
		Ti.API.error("dialog clicked!!");
		if (e.index === 0) {
			Ti.API.error("Index 0");
		}
	});
	dialog.show();

Actual Result

*iOS7* - The option dialog has no separator lines and when longpressing on the last item there appears to be space below this item *iOS8* - The option dialog has separator lines, when longpressing the last item there is no space below

Expected Result

*iOS7* -The option dialog should have separator lines, when longpressing the last item there should be no space below it. It should have parity with iOS8 *iOS8* - The option dialog has separator lines, when longpressing the last item there is no space below