This "domain fronting" trick could make Google suffer collateral damages if the regime is determined to block such encryption apps.
Blocking Google would make Dubai really look like a red headed step child, since they are trying to appeal to an international audience to do business and live in their country. Porn they are able to get away with blocking, but basic tools for business is unlikely to get blocked, especially since their competitors (Yandex & Baidu) are not popular there.