Add configuration option for environment variable "UPTIME_KUMA_DISABLE_FRAME_SAMEORIGIN" in Uptime Kuma Add-on

[newandreas]

Hello! I wanted to embed my Uptime Kuma in an iframe, but I can't find a way to set the "UPTIME_KUMA_DISABLE_FRAME_SAMEORIGIN" environment variable in the Uptime Kuma docker to true in Home Assistant.
I assume this would have to be added as a configuration option in the Add-on

https://github.com/louislam/uptime-kuma/wiki/Environment-Variables