Un-escaped ampersands in media URLs in google_newsstand feed

BLOX seems to have a bug where ampersands in media URLs are not escaped in the altf=google_newsstand version of the feed. The altf=verve_full version has them escaped properly with "&" but not the google_newsstand version. This causes it to fail XML validation and not get parsed by feed readers.

TownNews: I see you have fixed this issue in previous software releases for other feed versions (https://townnews.com/releases/software_releases/flex-templates-software-release---tues-sept-25th-2-00-pm-cdt/article_2abe4da6-bda8-11e8-a444-7f76286bc38c.html and https://townnews.com/releases/software_releases/blox-template-release---oct-7-2014---oct-9-2014/article_c46fb2fc-4d70-11e4-93ab-afa78a5be736.html) but it still needs to be fixed for google_news feeds.