fix: spelling

[hls-app]

Just the spelling and grammar fixes. No changes to the enum

List at least one fixed issue.

Pre-launch Checklist

• [✓] I made sure the project builds.
• [✓] I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• [✓] I updated pubspec.yaml with an appropriate new version according to the [pub versioning philosophy], or this PR is does not need version changes.
• [✘] I updated CHANGELOG.md to add a description of the change. Not sure if this tiny change deserve to be on the log.
• [✓] I updated/added relevant documentation (doc comments with ///).
• [✓] I rebased onto main.
• [✓] I added new tests to check the change I am making, or this PR does not need tests.
• [✓] I made sure all existing and new tests are passing.
• [✓] I ran dart format . and committed any changes.
• [✓] I ran flutter analyze and fixed any errors.

[mvanbeusekom]

LGTM, thank you for this contribution.