ecsobserver - extension doesn't have write permission to files in /etc directory

[FNaughton]

Hi all,
I'm trying to get the ecs_observer working with a prometheus receiver. I'm using AWS distro (ADOT) and running it in an ECS task.
Suggested config is to have a shared file in the /etc directory, but I get this error:

error ecsobserver@v0.117.0/extension.go:34 ECSDiscovery stopped by error { "kind": "extension", "name": "ecs_observer", "error": "open /etc/ecs_sd_targets.yaml: permission denied" }

I can probably workaround it by using the /tmp dir, but not sure this is the best path.
Anyone else have this experience, or who can suggest the preferred path?
Thanks