Create paired pre-upgrade and post-upgrade tests which create resources before upgrade and verify them after upgrade

[mgencur]

This is currently not the case because the pre-upgrade tests create its own set of resources and verify them, and post-upgrade tests create yet another set of resources and verify them. The resources from pre-upgrades do NOT live through the upgrades.

Problem

The only set of tests which create resources before upgrade and verify them later are the "continual" upgrade tests. The problem is that the test suite performs "downgrades" right after upgrades, so potential problems like https://github.com/knative-extensions/eventing-kafka-broker/issues/4034 are not caught because the problem is "fixed" again after downgrades.

The new upgrade tests should be added to the existing ones. They should follow this scenario:

• Create resources before upgrade
• Perform upgrade
• Verify the existing resources after upgrade
• Delete the resources (either directly or by deleting the test namespace)
• Create a new set of resources
• Perform downgrade
• Verify the existing resources after downgrade
• Delete the resources (either directly or by deleting the test namespace)

Persona: Developers/Testers

Exit Criteria Upgrade/downgrade tests working.

Time Estimate (optional): 2-3

Additional context (optional) Add any other context about the feature request here.

[Cali0707]

/triage accepted

[Cali0707]

/area test