He ded
Did a factory reset before this happened. I’m not really sure where to go from here. Apparently this is androids recovery mode?
Have you tried to flash the TV firmware? https://www.sony.com/electronics/support/product/xbr-55x850d/downloads even though that is Android 8 so this is only 4 versions behind.
Failing that then there is this long shot. https://www.hardreset.info/devices/sony/sony-xbr-55x850d/faq/firmware-flash/sony-firmware-change-repair-update-language-hardreset-phone-code-reset-hardreset/
r/Bravia
/u/MrAjAnderson is right, try putting the latest available firmware on a USB flash drive and then insert it into one of the TV's USB ports and power on the TV. If you're lucky it'll start installing the firmware and then reboot to a working state.
https://www.sony.com/electronics/support/downloads/00016747
Follow the instructions on the firmware download page for copying the firmware update to the USB flash drive.
If that doesn't work then you're looking at a new mainboard. Can be replaced on your own if you're tech savvy but the main problem will likely be locating one given the age of the TV.
This is why I keep my android in a box well away from the display.