Fix form clearing for company size

What does this MR do and why?

Fix form clearing for company size

Screenshots or screen recordings

This simply enables the correct default after a post for a re-post

handraisepql2-2021-10-08_09.58.25

Followup for !70044 (merged) Related to #334211 (closed)

How to set up and validate locally

1. In rails console enable the experiment fully

   Feature.enable(:in_app_hand_raise_pql)

2. In a gitlab.com-like environment, go to the billings section of a group
3. Click the Contact Sales button

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.