Make it more noticeable when the k8s watch fails

[mdouglass]

The resolver logs at error level if it gets an error code from k8s but if you have GPRC_TRACE turned off that its not obvious what's going on.

 Mar 13 20:07:05Z km-prod[prod3] km-events-6f4db9487-l9m5s[km-events] E 2024-03-13T20:07:04.363Z | v1.10.1 1 | k8s-resolver | watch start error {"code":403,"name":"Error","message":"HTTP-Code: 403\nMessage: Unknown API Status Code!\nBody: \"{\\\"kind\\\":\\\"Status\\\",\\\"apiVersion\\\":\\\"v1\\\",\\\"metadata\\\":{},\\\"status\\\":\\\"Failure\\\",\\\"message\\\":\\\"endpointslices.discovery.k8s.io is forbidden: User \\\\\\\"system:serviceaccount:prod3:eks-km-gateway\\\\\\\" cannot list resource \\\\\\\"endpointslices\\\\\\\" in API group \\\\\\\"discovery.k8s.io\\\\\\\" in the namespace \\\\\\\"prod3\\\\\\\"\\\",\\\"reason\\\":\\\"Forbidden\\\",\\\"details\\\":{\\\"group\\\":\\\"discovery.k8s.io\\\",\\\"kind\\\":\\\"endpointslices\\\"},\\\"code\\\":403}\\n\"\nHeaders: {\"audit-id\":\"974b3ee3-8829-4de5-b001-e8fc21036bc2\",\"cache-control\":\"no-cache, private\",\"connection\":\"close\",\"content-length\":\"375\",\"content-type\":\"application/json\",\"date\":\"Wed, 13 Mar 2024 20:07:04 GMT\",\"x-content-type-options\":\"nosniff\",\"x-kubernetes-pf-flowschema-uid\":\"852d6102-b113-4310-8bbd-a63ba1aac6d1\",\"x-kubernetes-pf-prioritylevel-uid\":\"cf220ef4-9b09-405c-9384-785c724fa75c\"}"}