[MOD-2398] Ti.WKWebView crash when selecting "Save Image"

When viewing a website in Ti.WKWebView, load any page with an image on it. You should be able to longpress on the image, and from the popup menu choose "Save Image" and it should save to the Camera Roll on the device. However it just crashes the app. For example load this url from the Appcelerator Blog into a Ti.WKWebView: https://www.appcelerator.com/blog/2018/02/building-titanium-apps-for-homepod/ Longpress on the "Tech Tip" image, and select "Save Image". The app will crash. The trace logs do not provide any clues. Here is some basic sample code:

var win = Ti.UI.createWindow();
var wkWebView = require('ti.wkwebview');
var webView = wkWebView.createWebView({
	url: 'https://www.appcelerator.com/blog/2018/02/building-titanium-apps-for-homepod/'
});
win.add(webView);
win.open();