fix(iot): Add namespaces to kuzstomization

This patch adds namespace definitions, in order to resolve the
Kubernetes objects properly. This will allow the expected patching to
work.

apps/base/iot/kustomization.yaml

 apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
+namespace: iot
 resources:
 - namespace.yaml
 - shelly-exporter.yaml

apps/k8s01/iot/kustomization.yaml

 apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
+namespace: iot
 resources:
 - ../../base/iot
 - certificate.yaml