Add hostAliases to template

[isak-lindbeck]

This enables hostAliases to be configured. https://kubernetes.io/docs/tasks/network/customize-hosts-file-for-pods/

Is for example useful when working with a sidecard proxy. The values configuration could look something like this:

hostAliases:
  - ip: "127.0.0.1"
    hostnames:
      - "schema-registry.localhost"

[Haarolean]

@isak-lindbeck thanks!