[Feature] add init container (include volume mount)

### Search before asking

- [x] I had searched in the [issues](https://github.com/apache/doris-operator/issues?q=is%3Aissue) and found no similar issues.

### Description

I am trying to deploy a compute-storage separated cluster where the storage layer is MinIO, and MinIO is deployed using the MinIO Operator. It enforces HTTPS for communication; for internal communication it defaults to using the Kubernetes CA, which Kubernetes mounts into all pods. The problem is Java does not trust that CA in the pod, so I need Doris to provide support for a custom init container so I can import that certificate into $JAVA_HOME/lib/security/cacerts.

### Use case

With minio

### Related issues

_No response_

### Are you willing to submit PR?

- [x] Yes I am willing to submit a PR!

### Code of Conduct

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