[native] Fix the styling of the QR URL screen on virtual devices

Summary:
Update the styling.

https://linear.app/comm/issue/ENG-10168/improve-qr-login-flow-on-dev

Depends on D14314

Test Plan: Check if the field is displayed correctly.

Reviewers: kamil, bartek

Reviewed By: kamil

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D14315