istio: Invalid env var marshalling in k8s resource spec

$ ik manifest generate --set values.pilot.env.ISTIOD_CUSTOM_HOST=1.2.3.4 -f ex.yaml
Error: could not unmarshal merged YAML: json: cannot unmarshal object into Go value of type []json.RawMessage

YAML:
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
metadata:
  namespace: external-istiod
spec:
  components:
    base:
      enabled: true
    cni:
      enabled: false
    egressGateways:
    - enabled: false
      name: istio-egressgateway
    ingressGateways:
    - enabled: true
      name: istio-ingressgateway
    istiodRemote:
      enabled: false
    pilot:
      enabled: true
      k8s:
        env:
          name: ISTIOD_CUSTOM_HOST
          value: 1.2.3.4

IOP:

    apiVersion: install.istio.io/v1alpha1
    kind: IstioOperator
    metadata:
      namespace: external-istiod
    spec:
      components:
        pilot:
          enabled: true
          k8s:
            env:

if env is removed, this doesn’t have issues

cc @morvencao