Fix usage overview visualization flex layout

What does this MR do and why?

Ensures we always display the contents as a row. The visualization container does not correctly resize the panel when switching flex direction, resulting in scrollbars.

This seems to have been there for a while but perhaps the md column class was not correctly applying previously, this now seems to be exposed by the CSS class migration in Migrate utility classes in dirs starting with A (!163782 - merged)

Credit

Full credit to @rcrespo3 for finding/discovering this as the cause 🙌🏾

MR acceptance checklist

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Screenshots or screen recordings

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Navigate to Analyze > Analytics dashboards for any group
2. Click on Value Streams Dashboard
3. The usage overview dashboard appears at the top of the page