Open ALB test listener results in a Critical-level Security Hub finding

[federicobond]

Describe the bug

The solution template configures an ALB test listener on port 8080 which is exposed to the world. This results in a Critical-level AWS Security Hub EC2.19 finding and does not align with Well-Architected Framework and other security standards recommendations.

The solution still works if the test listener is configured with open: false.

To Reproduce
Steps to reproduce the behavior:

1. Deploy the solution stack
2. Verify Security Hub EC2.19 finding

Expected behavior

The ALB test listener should not be exposed to the world.