[IcCard] - content added to slots not visible if slot initally empty

[ad9242]

Summary of the bug

Most of the slots in card do not show content if it is added after initial render

🪜 How to reproduce

Tell us the steps to reproduce the problem:

1. Go to stackblitz example
2. click on the toggle button
3. See only content in the heading, subheading and interaction-controls slots is visible there is no content visible in any of the following slots:

• message
• adornment
• image-top
• image-mid
• icon
• interaction-button
• expanded-content

now 5. click on the expand button 6. content in all slots is now visible all content is now visible

🧐 Expected behaviour

Any slot which starts empty & then has content added, should show the content

📝 Acceptance Criteria

The following applies to all slots in the component

Given a slot is initially empty When content is added to the slot Then the content should be visible