[stable/node-local-dns] feat: Add option to set securityContext

[zzorica]

Node-local-dns doesn't need to run in privileged mode and NET_ADMIN cap is enough. But just in case I am missing something this would set it as an option and leave privileged mode as "default".

To run in non-privileged mode in values this will do it:

securityContext:
  capabilities:
    add:
    - NET_ADMIN

Checklist

• Title of the PR starts with chart name (e.g. [stable/mychartname])
• I have read the contribution instructions, bumped chart version and regenerated the docs
• Github actions are passing

[max-rocket-internet]

OK cool, thanks @zzorica