[native] Remove async IIFE in CommunityDrawerContent effect

Summary:
This async IIFE was introduced in D7733. It's not clear to me why we need to await the Promise returned from dispatchActionPromise here, so I'm removing the await here.

If there's a reason for it, I can alternately add a void keyword preceding the async IIFE invocation to silence the unused-promise Flow lint.

Depends on D10173

Test Plan: Flow

Reviewers: tomek

Reviewed By: tomek

Differential Revision: https://phab.comm.dev/D10174