add filesystem group change policy for large minio deployments

[dharapvj]

Description

This change adds fsGroupChangePolicy: onRootMismatch for helm based minio deployments. This basically allows minio to skip checking the fsgroup changes - which can be rather slow operation

Motivation and Context

When using minio helm chart to deploy minio in Kubernetes cluster, if we have a large number of files in minio - e.g. greater than 300Gb, minio pod fails to come up due to PVC failing to get mounted.

We see below warning in kubelet logs for that node where pod is assigned:

W1220 05:32:58.485516    8703 volume_linux.go:52] Setting volume ownership for /var/lib/kubelet/pods/408ef833-2757-4807-a213-596706ddb0c5/volumes/kubernetes.io~vsphere-volume/pvc-573193ec-093a-4cd0-9f15-eed87faa3079 and fsGroup set. If the volume has a lot of files then setting volume ownership could be slow, see https://github.com/kubernetes/kubernetes/issues/69699

Going through kubernetes/kubernetes#69699 as suggested and linked documentation - it is suggested that we should set below setting for minio container.

  securityContext:
    fsGroupChangePolicy: "OnRootMismatch"

How to test this PR?

Deploy minio with a LOT of files in storage in kubernetes and delete the worker node so that minio is forced to move to different node.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Optimization (provides speedup with no functional changes)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• Fixes a regression (If yes, please add commit-id or PR # here)
• Documentation updated
• Unit tests added/updated

[minio-trusted]

Mint Automation

Test	Result
mint-large-bucket.sh	✔️
mint-fs.sh	✔️
mint-gateway-s3.sh	✔️
mint-erasure.sh	✔️
mint-dist-erasure.sh	✔️
mint-gateway-nas.sh	✔️
mint-compress-encrypt-dist-erasure.sh	✔️
mint-pools.sh	✔️
Deleting image on docker hub
Deleting image locally