[Self-Hosted][Docs] Update reference architectures to include AWS specific ELB timeouts

[mrzarquon]

Is your feature request related to a problem? Please describe

The default Classic load balancer behavior has a very short timeout that terminates the SSH session if left idle.

Describe the behaviour you'd like

Add instructions on how to use the customization of services with annotations to include:
service.beta.kubernetes.io/aws-load-balancer-connection-idle-timeout: "1800"

To the proxy service in cases where one is not using the ALB/NLB documentation. This should also be added to our corresponding testing infrastructure terraform

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.