Add API endpoint to reload the configuration

[amuntean-godaddy]

I am using cousul kv to manage the subscriptions configuration and consul-template to render the gnmi config in k8s. In case I change the subscriptions configuration in kv, the gnmi does not reload it's config and requires a manual re-deployments of the pods.

It will be great if you can add api endpoint to force the reload.

Example:
curl -X POST http://localhost:7890/-/reload

[karimra]

Something similar was added before see here
It respawns the whole pod but it will essentially achieve the same result.

[amuntean-godaddy]

Thanks @karimra

[amuntean-godaddy]

The only thing is that re-spawning the whole pod will take more time, which will result in a metrics gaps(~1m). I think with reloading config this time can be improved.