I have a CronJob defined in a yam file, deployed to istio as

apiVersion: batch/v1beta1
kind: CronJob
spec:
  schedule: "*/12 * * * *"

I want to have different schedules in different environments, so tried to set the schedule from a config map:

apiVersion: batch/v1beta1
kind: CronJob
spec:
  schedule: 
    - valueFrom:
        configMapKeyRef:
          name: config-name
          key: service-schedule

It fails to sync with the error

invalid type for io.k8s.api.batch.v1beta1.CronJobSpec.schedule: got "array", expected "string"

Is it possible to use config map in this way?