Password specified in clear text in OUD helm values.yaml

[jayrajput]

Following steps in https://github.com/oracle/fmw-kubernetes/blob/master/OracleUnifiedDirectory/kubernetes/helm/oud-ds-rs/README.md suggest to specify the rootUserPassword in clearText which our security team has raised concern. Preferred is to let the application use the K8s REST API sent to the API Server to read the password from k8s secret. The mounting of the secret is also considered to be insecure as the password is exposed in the environment variable.