Update documentation for httpsRedirect to include the redirect in the http section and not the https section. (#1463)

Author: mikehelmick

docs/serving/using-cert-manager-on-gcp.md

@@ -259,14 +259,17 @@ spec:
       protocol: HTTP
     hosts:
     - "*"
+    tls:
+      # Sends 301 redirect for all http requests.
+      # Omit to allow http and https.
+      httpsRedirect: true
   - port:
       number: 443
       name: https
       protocol: HTTPS
     hosts:
     - "*"
     tls:
-      httpsRedirect: true # sends 301 redirect for http requests.
       mode: SIMPLE
       privateKey: /etc/istio/ingressgateway-certs/tls.key
       serverCertificate: /etc/istio/ingressgateway-certs/tls.crt