Inherit Storage Class for Scratch Space PVCs

[Dsanatar]

What this PR does / why we need it:
There are some scenarios where we would like scratch space PVCs to use the same storage class as the associated target PVC instead of falling back to the default storage class.

This PR adds a new feature gate InheritScratchSpaceStorageClass which when enabled, allows scratch space PVCs to inherit the storage class from the target PVC.

The config controller currently looks to see that the config.Spec.ScratchSpaceStorageClass is set and if it is not, it will set it to the default storage class. However, now when this new feature gate is enabled, it will instead set it to be empty.

From here, there is existing code that checks to see if this ScratchSpaceStorageClass is not set, it will use the storage class from the owner PVC

containerized-data-importer/pkg/controller/util.go

Lines 237 to 243 in c309762

	storageClassName := config.Status.ScratchSpaceStorageClass
	if storageClassName == "" {
	// Unable to determine scratch storage class, attempt to read the storage class from the pvc.
	if pvc.Spec.StorageClassName != nil {
	storageClassName = *pvc.Spec.StorageClassName
	if storageClassName != "" {
	return storageClassName

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

Release note:

add new InheritScratchSpaceStorageClass feature gate

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