Flow Customisation: add cancel reasons to the cancel journey

The cancel journey requires specifying a reason for cancelling. This is presented as a dropdown menu to choose from when performing the cancel action:

The value set for the picklist is dynamically determined by the custom metadata value stored in the Subscription Action metadata of ic Assist Config

Values being rendered are listed in the cancelReasons array, and then retrieved in apex by the class "Get Cancel Reasons" and then stored in the flow variable CancelReasons.

The CancelReasons flow variable is of type list of i42as__PicklistChoice.

If cancel reasons are stored somewhere else, it's possible to replace this apex action with another custom action, as long as the results are of the same type i42as__PicklistChoice and then stored in the flow variable CancelReasons. The Cancel Screen flow element will read this value and render the list dynamically.