HELM: Allow minio to use docker pull secret

[mdef]

trafficstars

What

Allow minio deployment to use docker pull secret and solve docker hub download rate limits

How

If main_container_image_pull_secret variable exists add imagePullSecrets block into minio deployment

Recommended reading order

N/A

Can this PR be safely reverted / rolled back?

If unsure, leave it blank.

• [X] YES 💚
• [ ] NO ❌

🚨 User Impact 🚨

Are there any breaking changes? What is the end result perceived by the user? If yes, please merge this PR with the 🚨🚨 emoji so changelog authors can further highlight this if needed.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}