Draft: adding coral device-type and healthcheck

Added the device type to etc/dispatcher-config/device-types and health check to etc/dispatcher-config/health-checks

Followed the new guide https://gitlab.collabora.com/lava/collabora-lava-setup/-/blob/master/doc/lava-admin.md. I had to create the folder for etc/dispatcher-config/health-checks, hence only the new healthcheck is in there. I guess this is mostly for review and will not overwrite the current config on Titanium.