Update public preview section in what's new document

[juntakata]

The title "Public Preview - Cloud Managed Remote Mailboxes" is not correct. My team got an inquiry from the customer regarding this discrepancy. Please fix the title of this section.

[prmerger-automator]

@juntakata : Thanks for your contribution! The author(s) and reviewer(s) have been notified to review your proposed change.

[learn-build-service-prod]

Learn Build status updates of commit 18acfc8:

💡 Validation status: suggestions

File	Status	Preview URL	Details
docs/fundamentals/whats-new.md	💡Suggestion		Details

docs/fundamentals/whats-new.md

• Line 99, Column 122: [Suggestion: preserve-view-not-set - See documentation] You've pinned this link to a specific version of content with the view parameter. It's recommended not to pin a version unless that version is A) not the default view and B) the context is about that version specifically. To proceed with pinning a version add the &preserve-view=true to the URL. Otherwise, remove the view parameter. URL: /graph/api/resources/privilegedidentitymanagement-root?view=graph-rest-beta
• Line 116, Column 3: [Suggestion: preserve-view-not-set - See documentation] You've pinned this link to a specific version of content with the view parameter. It's recommended not to pin a version unless that version is A) not the default view and B) the context is about that version specifically. To proceed with pinning a version add the &preserve-view=true to the URL. Otherwise, remove the view parameter. URL: /graph/api/resources/privilegedidentitymanagement-root?view=graph-rest-beta
• Line 117, Column 3: [Suggestion: preserve-view-not-set - See documentation] You've pinned this link to a specific version of content with the view parameter. It's recommended not to pin a version unless that version is A) not the default view and B) the context is about that version specifically. To proceed with pinning a version add the &preserve-view=true to the URL. Otherwise, remove the view parameter. URL: /graph/api/resources/privilegedidentitymanagement-root?view=graph-rest-beta#migrate-from-pim-iteration-2-apis-to-pim-iteration-3-apis

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[ktoliver]

@OWinfreyATL

Can you review the proposed changes?

IMPORTANT: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged"
@MicrosoftDocs/public-repo-pr-review-team