[web] Use hook instead of connect function in Splash

Test Plan: Checked if the splash screen still showed up, and worked properly such as logging in, and selecting things such as the request access select for android or ios.

Reviewers: palys-swm, ashoat, atul

Reviewed By: ashoat

Subscribers: ashoat, KatPo, zrebcu411, Adrian, atul

Differential Revision: https://phabricator.ashoat.com/D816