How do I update to the most recent Android version? I bought a Fitbit Versa 2 and cannot "set up device" on my phone because the Android version is to old. My phone has 6.0.1 and I at least have to have 7 or higher to use the Fitbit device. When I tried "System Update" it states I have the current version available and that it was last updated on 9/3/17. No system updates in over 2 years? My phone is a ZTE ZMAX PRO, model #Z981. I've emailed ZTE Corporate but haven't and may never receive a reply. Please advise/help!