fix wording to be more clear per docs request

[xyh1]

see issue https://github.com/MicrosoftDocs/azure-docs/issues/31203

Description

Changed text descriptions to be more clear that is is for removing unlocked immutability policies

Checklist

• I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate change log has been updated
• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • the changes have gone through a cmdlet design review (Microsoft internal partners only)
  • the cmdlet markdown files were generated using the platyPS module

[adxsdkps]

Can one of the admins verify this patch?

[niander]

@xyh1 Hi. Could you add a changelog entry?

[niander]

@xyh1 The changelog entry was in the wrong place. I moved it for you. I will approve the PR. Should we wait for @blueww approval as well?

[xyh1]

@niander Thanks for the help! You can just push without another review from Wei.