[bug] Accordion fixed panel variant

[zeroedin]

Description of the issue

The fixed panel variant of the Accordion does not behave as intended. The panel is not open on load.

Impacted component(s)

• Accordion

Steps to reproduce

1. View Accordion demo compare to functionality on https://www.patternfly.org/v4/components/accordion/

Expected behavior

The fixed panel should be open on load

Screenshots

[brianferry]

I believe this is because the fixed panel does not have an expanded tag put onto the first header like the single expanded has. We can add it into the demo though