T28267 set colorbar placement to correct height
Summary: Solves T28267. Colorbars were by default cut off at the top. By adjusting the hardcoded placement slightly it is fully within view
Test Plan: Manual testing (open Overlay Manager, click plus, select colorbar)
Reviewers: kalali
Reviewed By: kalali
Subscribers: thomass, kalali
Differential Revision: https://phabricator.mitk.org/D506