Change KafkaChannel defaults for partition and replica

[matzew]

Problem
The current defaults for setting partitions and replica to 1 is a pretty poor choice.

We noticed in tests that it is much much better if we default to something like 10 partitions and 3 replica

The issue here is that 3 replica does not work single broker instances, but those are generally considered being a toy.

For POCs or demos, the replica can be still configured to be 1, on the actual KafkaChannel object - so single broker usage is still possible

Persona:
Which persona is this feature for?

Exit Criteria
A measurable (binary) test that would indicate that the problem has been resolved.

Time Estimate (optional):
How many developer-days do you think this may take to resolve?

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

[pierDipi]

I can bring this in today's Kafka WG call if you won't join.

[aliok]

I don't have a strong opinion.

• Defaults that are good for getting started: prod users should set the config
• Defaults that are better for prod: getting-started-users should set the config

I think I would still prefer option 1, but I am ok with it both

[travis-minke-sap]

I'm ok either way ; )
(fwiw - we set them in all KafkaChannel instances for our production use cases)

[matzew]

FWIW, we have the same defaults on the knative kafka broker

[pierDipi]

/reopen

[knative-prow-robot]

@pierDipi: Reopened this issue.

In response to this:

/reopen

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[github-actions]

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fresh by adding the comment /remove-lifecycle stale.

[pierDipi]

/remove-lifecycle stale
/triage accepted