Using a variable in the namespace of a generated resource

I've created a policy that generates Services for every Deployment in a namespace. The one thing I can't figure out is that it's a Policy rather than a ClusterPolicy and I want to make the namespace attribute dynamic. (Because the policy is part of a Kustomize overlay that's used to define qa and prod environments.) It doesn't seem to be intepreting the variables in this field prior to validating the policy though:

admission webhook "validate-policy.kyverno.svc" denied the request: path: spec.rules[create-service]: a namespaced policy cannot generate resources in other namespaces, expected: bradmac-integration-platform, received: {{ request.object.metadata.namespace }}

apiVersion: kyverno.io/v1
kind: Policy
metadata:
  name: auto-generate-services
  annotations:
    policies.kyverno.io/title: Autogenerate services for deployments
    policies.kyverno.io/category: Argo
    policies.kyverno.io/severity: medium
    policies.kyverno.io/subject: Deployment, Service
    policies.kyverno.io/description: >-
      This policy generates `Service`s automatically based on `Deployment`s.
spec:
  generateExistingOnPolicyUpdate: true
  rules:
    - name: create-service
      match:
        all:
          - resources:
              kinds:
                - Deployment
      generate:
        apiVersion: v1
        kind: Service
        name: "{{ regex_replace_all('-deploy', request.object.metadata.name, '') }}-service"
        namespace: "{{request.object.metadata.name}}" # <- this variable isn't being interpolated
        synchronize: true
        data:
          metadata:
            ownerReferences:
              - apiVersion: v1
                kind: Deployment
                name: "{{ request.object.metadata.name }}"
                uid: "{{request.object.metadata.uid}}"
          spec:
            selector:
              app: "{{ regex_replace_all('-deploy', request.object.metadata.name, '') }}"
            ports:
              - port: 80
                targetPort: 8085
                protocol: "TCP"
            type: ClusterIP

Anyone know of any workarounds so that this can work for whatever namespace the overlay places it in?