Came across this issue where AP with image 8.10.130.0 could not upgrade from WLC due to low disk space.
Workaround – upgrade to 17.3.7 first over TFTP and then it will reboot and upgrade from controller.
Cisco Wireless Solutions Software Compatibility Matrix – here. You will need this to figure out which AP image file to download to match 17.3.7.
Then find and download it on Cisco.
Command to download file to AP.
archive download-sw /reload tftp://<TFTP_serverIP>/ap1g6a-k9w8-tar.153-3.JPJ10.tar
I’ve booted AP on DHCP scope without WLC info so it does not join it and try upgrading interfering with copy process as it take some time with TFTP.