Room Creation Intro Cell does not transition from Light to Dark Mode and back

[mgcm]

Steps to reproduce

1. Log in to Element iOS
2. Create a new room or select a room with little to no history in the timeline
3. See the empty timeline and the room creation intro cell in the top
4. Put the app into the background
5. Wait until there is a theme change from Dark to Light or Light to Dark or force a change in system settings
6. Go back into Element and you will see that all of the UI components have changed its theme except the top room creation intro header cell

Outcome

What did you expect?

All the UI components should update its themeing without having to leave the room or restart the app

What happened instead?

The Room Creation Intro cell does not adjust its theme to the active system theme when it changes without leaving the timeline view.

See the attached GIF animation:

Your phone model

All iPhones

Operating system version

iOS 14+

Application version

develop branch

Homeserver

not relevant

Will you send logs?

No

[mgcm]

PR #7555 fixes this