Update smack test runner to default to custom gradle
Update smack test runner to default to custom gradle

Latest versions of gradle fail to build the tests. This is a cheap fix.
guusdk/Openfire,guusdk/Openfire,guusdk/Openfire,guusdk/Openfire,igniterealtime/Openfire,guusdk/Openfire,akrherz/Openfire,igniterealtime/Openfire,akrherz/Openfire,igniterealtime/Openfire,igniterealtime/Openfire,igniterealtime/Openfire,akrherz/Openfire,akrherz/Openfire,akrherz/Openfire