[web] [fix] input bar on multiline text input and image uploader

Summary: fixes current regression in web

Test Plan: add multiline text, drag and drop image, upload image. It all should work

Reviewers: atul, ashoat

Reviewed By: ashoat

Subscribers: ashoat, palys-swm, Adrian, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D3115