Once you've purchased the subscription it enables Auto-Assist to all users of the house, no matter if they use iOS or Android. Your account still has it enabled. If you are expreriencing any issue using it, please contact our support.
What you need to consider is that the purchase you made was from the App Store, so your Play Store account won't have any record from this. If you are no longer using iOS, we'd recommend to cancel its renewal (you can do it from iTunes, without an iOS device). And once the current subscription expires, if you are interested in renewing it, then purchase it from the Play Store in your Android device.