Fix Chat Placeholder style implementation for virtual keyboard on Webkit to function as expected

[GigiaJ]

Description

Swaps from pulling out the style (which seems to be LAF versus just Look) This allows Slate to apply its "feel" which handles Webkit appropriately.

Fixes # #2345

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] My changes generate no new warnings