Description of problem (please be detailed as possible and provide log
snippests):
As requested in https://bugzilla.redhat.com/show_bug.cgi?id=2005830#c40
this bug is being raised for the error message improvement when editing few immutable fields (ReplicationClassSelector and VolumeSnapshotClassSelector) in DRPolicy

Version of all relevant components (if applicable):
OCP: 4.13.0-0.nightly-2023-06-15-092245
ODF: 4.13.0-219
ACM: 2.8.0
Submariner: 0.15.1

Does this issue impact your ability to continue to work with the product
(please explain in detail what is the user impact)?
No

Is there any workaround available to the best of your knowledge?


Rate from 1 - 5 the complexity of the scenario you performed that caused this
bug (1 - very simple, 5 - very complex)?
1

Can this issue reproducible?
Yes

Can this issue reproduce from the UI?
Yes

If this is a regression, please provide more details to justify this:


Steps to Reproduce:
1. Deploy RDR setup
2. Create a DRPolicy
3. Try to edit ReplicationClassSelector and VolumeSnapshotClassSelector fields in DRPolicy via UI
4. Try to edit ReplicationClassSelector and VolumeSnapshotClassSelector fields in DRPolicy via CLI

Actual results:
No error message when trying to edit above mentioned immutable fields

Expected results:
Error message should be shown when trying to edit any immutable field

Additional info:
See https://bugzilla.redhat.com/show_bug.cgi?id=2005830#c35 for UI output
See https://bugzilla.redhat.com/show_bug.cgi?id=2005830#c38 for CLI output