[native] Simplify SIWEPanel component
Summary: There was a bunch of stuff in this component that seemed completely unnecessary. Just quickly stripped it out to simplify things since I'm modifying this file.
Test Plan:
- Clean build + clear caches
- Able to hit SIWE button
- Things open and continue to work as expected
Reviewers: ashoat, tomek
Reviewed By: ashoat
Differential Revision: https://phab.comm.dev/D5950