[native] Use hook instead of connect function and HOC in CustomServerModal

Test Plan: Tested to see if modal still popped up and pressing go still worked

Reviewers: palys-swm, ashoat

Reviewed By: ashoat

Subscribers: ashoat, KatPo, zrebcu411, Adrian, atul, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D801