[Karpenter] Fix ignored namespace prop

[muckelba]

I've stumbled across a bug while installing karpenter: I can set the namespace in the KarpenterAddOnProps, but the createNamespace() and createServiceAccount() functions would still use the default variable as their namespace.

[shapirov103]

@youngjeong46 please have a look, I see you have hardcoded the namespace, was there a particular reason for it?

[shapirov103]

/do-e2e-tests