Sharing: update Skype button to support Microsoft Teams

With the announcement from Microsoft about Skype for business becoming Microsoft Teams, are we planning to change the Skype button to Microsoft Teams or add an extra "Microsoft Teams" button to the post sharing options?

https://techcommunity.microsoft.com/t5/healthcare-and-life-sciences/skype-for-business-online-end-of-life-july-31-2021/ba-p/779137

https://docs.microsoft.com/en-us/microsoftteams/faq-journey

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Reported in 2970429-zen

No file, test, or entry point is named. Start by locating the post sharing options and reviewing how the existing Skype button is represented; clarify whether the expected result is replacing Skype with Microsoft Teams or adding a separate button, then verify the chosen behavior in the sharing UI.

Written by the indexing model from the issue text.