[fix][broker] Fix create ns

[nodece]

Motivation

Namespace policy is ignored if the namespace is created directly by the NamespaceResources.

Modifications

• Use admin to create a namespace instead of the NamespaceResources

Documentation

• [ ] doc-required (Your PR needs to update docs and you will update later)

• [x] doc-not-needed (Please explain why)

• [ ] doc (Your PR contains doc changes)

• [ ] doc-complete (Docs have been already added)

Matching PR in forked repository

https://github.com/nodece/pulsar/pull/4

[nodece]

/pulsarbot rerun-failure-checks