License key form incorrectly displays when there's a pending change request for key-related fields

[Anthony Lenton]

Enabling license key infrastructure for an app once it's past review is quite confusing at the moment. To reproduce this bug, try the following:

- Create a new application, leaving license key infrastructure disabled.
- Submit for review
- As a reviewer, approve the app. Leaving it in QAPending state is enough, just so that changes need to be approved separately in an ApplicationChangeRequest, instead of being applied directly to the app.
- As the application registrant, go to the "License Keys" tab, provide a license key path and a bunch of license keys, and click "Start using license keys"

ER: The form would display as if license keys were already enabled, but display a warning message "this form includes changes that are still pending review" like the one you get on the application details page when there are pending changes. Alternatively, just display a sign saying that "your changes have been submitted for review", display the submitted changes, and offer a button to cancel the change request.

AR: The form displays as if license keys weren't enabled, and offers the developer to enable License key infrastructure, even though the form for enabling license key infrastructure has just been submitted successfully.