Make sure drafts are not persisted via redux-persist but a placeholder is created upon rehydration

Summary: This differential prevents drafts from being persisted in redux persist

Test Plan: Make sure eslint and flow do not point errors. This is trival test plan, but no other is possible before we implement relevant reducers.

Reviewers: tomek, atul, ashoat

Reviewed By: tomek, ashoat

Subscribers: ashoat, abosh

Differential Revision: https://phab.comm.dev/D5645