Adding new podlabels can break kiam-agent daemonset

[harshal-shah]

We wanted to add new labels to kiam pods and we found that adding .Values.agent.podLabels updates the .spec.selector as well as .spec.template.metadata.labels which causes us to recreate the agent daemonset.

This happens due to these lines

In the server daemonset, this problem does not exist, as the server daemonset applies podLabels only on .spec.template.metadata.labels

I can send a PR to fix this, but it can potentially break users who are already using .Values.agent.podLabels as their daemonsets would need to be recreated.