Update documents to better describe the SpeakerAttributionMode policy value

[sunnyden]

We are the owner of Teams transcription/captions feature.

We found that the current documentation of SpeakerAttributionMode may be confusing and I have updated the document to better reflect the followings:

• All setting values apply to captions and transcripts (including copilot-only transcript).
• The default value of this meeting policy is EnabledUserOverride. Users by default will be identified in transcripts and captions.

Please help review it. Thanks.

[learn-build-service-prod]

Learn Build status updates of commit 62f3dd0:

✅ Validation status: passed

File	Status	Preview URL	Details
teams/teams-ps/MicrosoftTeams/Set-CsTeamsMeetingPolicy.md	✅Succeeded	View (teams-ps)

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