helm: allow container port configuration

[alemorcuq]

Description of the change
The container and host ports are now configurable in the Helm chart. As per the docs, when hostNetwork is enabled, the host ports are set equal to the container ports.

$ kubectl explain po.spec.containers.ports

[...]
   hostPort	<integer>
     Number of port to expose on the host. If specified, this must be a valid
     port number, 0 < x < 65536. If HostNetwork is specified, this must match
     ContainerPort. Most containers do not need this.
[...]

Benefits
Users can configure the ports to use.

Possible drawbacks

Applicable issues

• fixes Allow overriding hostport when using hostNetwork #1596