Add additional Init Containers and Volume Mounts

[askoriy]

What was changed

Add the option co configure additional init containers and volume mounts

Why?

In our case to get certificates from Vault and mount as files

Checklist

1. Closes

2. How was this tested:

3. Any docs updates needed?

[CLAassistant]

All committers have signed the CLA.

[enricojonas]

@robholland @askoriy can we get this merged? We need this functionality.

We would also like to propagate the server init containers to the server job. That way, if you use any proxy for example, it can be used during DB creation, schema setup and update.

helm-charts/charts/temporal/templates/server-job.yaml

Line 26 in 4d90e8a

initContainers:

        {{- if $.Values.server.initContainers }}
        {{- toYaml $.Values.server.initContainers | nindent 8 }}
        {{- end }}

Let me know if you can include it or if you want me to push a commit to this branch.