Update SavedChangesMessage styling

What does this MR do?

This MR cleans up styling related to the feedback from these mockup changes #212379[08_Success.png]

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content