Glad your issue is resolved. I'm just posting this to add-on/answer one of your comments.
While they ask for which model of phone you use, information for both iOS and Android are always sent out, just in case you switch phone models during the Alpha/Beta. Upon sponsoring, you should receive 2 e-mails:
Email from Test Flight - Test Flight app is needed to test out any iOS app.
Email with actual Alpha key - This email gets caught by spam filters very often.
No email is sent specifically for Android as there is nothing special you need to do in order to test android app's.