MNTOR-3164 - “Submit Form” button for the cancel survey is cut

[mozilloid]

References:

Jira: MNTOR-3164
Figma:

Description

Changed the default feedback text iFrame height to 280px, and 260px for large screens. - this way the submit button seems to be visible for any change in textbox size, while also not looking weird. NEEDS verification on windows device

Screenshot (if applicable)

How to test

Go to premium account's settings, click on cancel subscription (locally, enable the appropriate feature flags).

Checklist (Definition of Done)

• Localization strings (if needed) have been added.
• Commits in this PR are minimal and have descriptive commit messages.
• I've added or updated the relevant sections in readme and/or code comments
• I've added a unit test to test for potential regressions of this bug.
• If this PR implements a feature flag or experimentation, the Ship Behind Feature Flag status in Jira has been set
• Product Owner accepted the User Story (demo of functionality completed) or waived the privilege.
• All acceptance criteria are met.
• Jira ticket has been updated (if needed) to match changes made during the development process.
• Jira ticket has been updated (if needed) with suggestions for QA when this PR is deployed to stage.

[github-actions]

Preview URL 🚀 : https://blurts-server-pr-4641-mgjlpikfea-uk.a.run.app

[codemist]

Well done!

[github-actions]

Cleanup completed - database 'blurts-server-pr-4641' destroyed, cloud run service 'blurts-server-pr-4641' destroyed