Todo
Improve documentation for https://docs.redhat.com/en/documentation/red_hat_openshift_serverless/1.33/html/serving/external-and-ingress-routing#interacting-serverless-apps-http2-grpc_using-http2-gRPC.

Things to change
1. Drop the following hints (as OCP 4.10 is no longer supported):

This method applies to OpenShift Container Platform 4.10 and later. For older versions, see the following section.

Upgrade OpenShift Container Platform 4.10 or later.

2. Add a clarification that this is only valid if `kourier` is the networking layer. If istio is used, this documentation does not apply.