Add container security context to tenant crd and helm chart

[LeadingMoominExpert]

Hi folks! With this PR I'm trying to address the issue described in here #1267 & #1310

Currently there is no way to pass full container level security context when deploying a tenant. This feature would be similar to the one pending for the operator and the console #1278

This is my first trying contributing here, so any pointers on what I'm missing here are more than welcome.

[dilverse]

@LeadingMoominExpert did you get a chance to test this changes with Kubernetes version 1.20/1.21?

[dvaldivia]

I think we should add this on a per Pool basis similar to the already existing SecurityContext which gets applied to the Pod only across all the pods in the pool.

[LeadingMoominExpert]

@LeadingMoominExpert did you get a chance to test this changes with Kubernetes version 1.20/1.21?

I did not, no. Which versions I should check for, up from 1.20?

[dilverse]

@LeadingMoominExpert Thanks for your contribution, this issue is addressed in a much robust way in PR #1372. Will close this PR