Fix #14692: Saving changes to a story without a commit message results in an error

[Lawful2002]

Overview

1. This PR fixes Saving changes to a story without a commit message results in an error #14692.
2. This PR does the following: Fixed the spelling of [disabled]

Essential Checklist

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Proof that changes are correct

oppia-modal.mp4

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[oppiabot]

Hi, @Lawful2002, this pull request does not have a "CHANGELOG: ..." label as mentioned in the PR pointers. Assigning @Lawful2002 to add the required label. PRs without this label will not be merged. If you are unsure of which label to add, please ask the reviewers for guidance. Thanks!

[Rijuta-s]

Thanks @Lawful2002! LGTM.

[oppiabot]

Assigning @EricZLou for code owner reviews. Thanks!

[EricZLou]

LGTM thanks!

[oppiabot]

Unassigning @EricZLou since they have already approved the PR.

[oppiabot]

Hi @aks681, this PR is ready to be merged. Author of this PR does not have permissions to merge this PR. Before you merge it, please make sure that there are no pending comments that require action from the author's end. Thanks!