[ENHANCEMENT] Support AWS NLB with TLS Termination

[aabouzaid]

Describe the use case:

We need to check what's needed config to run Camunda Platform 8 on AWS NLB with TLS Termination.

The flow looks like the following:

User --(HTTPS)--> NLB --(HTTP)--> Ingress-NGINX --(HTTP)--> Camunda services

The main issue will be in Keycloak since it doesn't get a direct HTTPS connection which means some headers could be missing.

Desired outcome and acceptance tests:

Camunda Platform 8 should work with AWS NLB with TLS Termination (that could be a matter of docs since we don't manage the Ingress controller directly).