Fix smaller height of Activity header page

What does this MR do?

Fix smaller height of Activity header page.

Why was this MR needed?

It looks inconsistent.

Screenshots (if relevant)

Screenshot is attached in issue #27631 (closed).

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #27631 (closed).