Default Kyma Gateway works with dualstack Istio

[strekm]

Description

Extend Kyma Default Gateway functionality with proper configurations needed for dualstack. Kyma Default Gateway has dependency to Istio Ingress Gateway, which has dualstack support in experimental offering. API Gateway controller should react on configuration of Istio Ingress Gateway and configure default gateway accordingly.

ACs:

• Kyma Default Gateway properly configured depending on Istio Ingress Gateway
  TODOs:
• annotate Gardener DNSEntry if Istio Ingress Gateway has ipv6
• extend documentation

Reasons

dualstack support

PR

• Support for istio ingress running in IPv6 and DualStack #2592