Content Experiment Groups are not collapsible

[ihor-romaniuk]

Steps to reproduce:

• Enable the "Content Experiment" component by adding "split_test" to Advanced module list on Advanced settings page
• Set up "Experiment group configurations" on Group configurations page
• Add a new Content Experiment component from Advanced components to the unit.
• Configure the Content Experiment by selecting a group.
• Save the changes and click the “View” button to open the Content Experiment inner page.
• Click on the group chevron button at the top of the group.

Actual behaviour:
The Collapse chevron button on the Content Experiment page does not perform. When clicked, it probably should collapse group content on the page.

Expected behaviour:
The Collapse chevron button should either perform a collapsing function or be removed.

Screenshot:

[jmakowski1123]

Is this behavior only happening with the randomized block with V1/legacy libraries?