You can use helm post-install hook: https://helm.sh/docs/topics/charts_hooks/

Just add the "helm.sh/hook": post-install annotation.

For example:

apiVersion: batch/v1
kind: Job
metadata:
  name: "{{.Release.Name}}"
  labels:
    app.kubernetes.io/managed-by: {{.Release.Service | quote }}
    app.kubernetes.io/instance: {{.Release.Name | quote }}
    app.kubernetes.io/version: {{ .Chart.AppVersion }}
    helm.sh/chart: "{{.Chart.Name}}-{{.Chart.Version}}"
  annotations:
    # This is what defines this resource as a hook. Without this line, the
    # job is considered part of the release.
    "helm.sh/hook": post-install
    "helm.sh/hook-weight": "-5"
    "helm.sh/hook-delete-policy": hook-succeeded
spec:
  template:
    metadata:
      name: "{{.Release.Name}}"
      labels:
        app.kubernetes.io/managed-by: {{.Release.Service | quote }}
        app.kubernetes.io/instance: {{.Release.Name | quote }}
        helm.sh/chart: "{{.Chart.Name}}-{{.Chart.Version}}"
    spec:
      restartPolicy: Never
      containers:
      - name: post-install-job
        image: "alpine:3.3"
        command: ["/bin/sleep","{{default "10" .Values.sleepyTime}}"]

Why not just use a Job? Isn't that exactly what you're looking for? Why even complicate it with a post commit hook. Does it have to be after the container is established? A job runs once and then is terminated.