Fix ACL check on health endpoint
Prior to this change, the service health API would not explicitly return an
error whenever a token with invalid permissions was given, and it would instead
return empty results. With this change, a "Permission denied" error is returned
whenever data is queried. This is done to better support the agent cache, which
performs a fetch backoff sleep whenever ACL errors are encountered. Affected
endpoints are: `/v1/health/connect/` and `/v1/health/ingress/`.
