gRPC conformance: specify appProtocol (#2968)

This is already used for `infra-backend`, and is codified in Kubenetes
(https://kubernetes.io/docs/concepts/services-networking/service/#application-protocol)

Author: howardjohn

conformance/base/manifests.yaml

@@ -533,6 +533,7 @@ spec:
   - protocol: TCP
     port: 8080
     targetPort: 3000
+    appProtocol: kubernetes.io/h2c
 ---
 apiVersion: apps/v1
 kind: Deployment
@@ -582,6 +583,7 @@ spec:
   - protocol: TCP
     port: 8080
     targetPort: 3000
+    appProtocol: kubernetes.io/h2c
 ---
 apiVersion: apps/v1
 kind: Deployment
@@ -631,6 +633,7 @@ spec:
   - protocol: TCP
     port: 8080
     targetPort: 3000
+    appProtocol: kubernetes.io/h2c
 ---
 apiVersion: apps/v1
 kind: Deployment