Update RBAC for tainer in helm charts

[kunal-511]

Pull Request Template for Kubeflow Manifests

✏️ Summary of Changes

Update helm charts values for trainer

🐛 Related Issues

fix helm charts errors in kubeflow#3199

✅ Contributor Checklist

• I have tested these changes with kustomize. See Installation Prerequisites.
• All commits are signed-off to satisfy the DCO check.
• I have considered adding my company to the adopters page to support Kubeflow and help the community, since I expect help from the community for my issue (see 1. and 2.).

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[ram4444]

lgtm