Add trafficDistribution support to the gateway and agent services

[dmitryax]

Replaces #1772

[jinja2]

Can you add this config in one of our examples? Tmk, this config is only introduced in a recent version of k8s and i think kubeconform output would shed some light on version support for this. I think this might require a note or check for min k8s version

[dmitryax]

Can you add this config in one of our examples? Tmk, this config is only introduced in a recent version of k8s and i think kubeconform output would shed some light on version support for this. I think this might require a note or check for min k8s version

Apparently it's only available since 1.33 and our tests are still at 1.31. So adding it to examples would be failing. I added a note in the comments

[jinja2]

Suggested change

	{{- if .Values.service.trafficDistribution }}
	{{- if and .Values.service.trafficDistribution (semverCompare ">=1.33.0-0" .Capabilities.KubeVersion.Version) }}

We could additionally verify in template but the clarification in comment is also good with me.

[dmitryax]

I think it's fine to fail rather then suppressing the user error.