We are working on a android 7.1.2 running on i.mx6 platform. We tried to do Android OTA update to change the version of the software. Software was downloaded from our server and then it proceeded for installation. It rebooted the system. There we could see Rings rotating with the progress bar. After some progress, progress bar got stuck at 80%.
On terminal i could only see that it was booted with recovery command with starting kernel message.
Unfortunately, we do not support Android OTA. For more information, I hardly suggest you go with google they could help you in a better way. Furthermore, for more information, you could see section 7 of our reference manual. I apologize for the inconveniences this could give you.