[Gotthard2][Correct] Store mask data properly for gotthard2 25um

Description

@mramilli reported a bug in the offline correction where the mask is stored with the wrong number of stripes.

It seems I made the mistake of forgetting about storing the mask after interleaving in the same way it is done for the data and gain.

This fix has a high priority as it needs to be available for the users by next week.

How Has This Been Tested?

• HOTFIXED in production

Relevant Documents (optional)

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

Reviewers

@hammerd @schmidtp