[chore] added scrollbar-gutter: stable for storybook preview container

[ilyabrower]

Motivation and Context

I need this fix for the theme-comparer - to display test components without unnecessary horizontal scroll

How has this been tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).
• Nice improve.

Checklist:

• I have updated the documentation accordingly.
• I have added new tests on added of fixed functionality.