Microsoft.UI.Xaml v2.7.2

https://www.nuget.org/packages/Microsoft.UI.Xaml/2.7.2

This resolves an issue where there was a conflict between the framework package in the nuget package and the framework package in the Store.

Changes:

• f8c0a6a Update PhoneIdentity for 2.7 (#7407)
• 4aec1dd Bump version to 2.7.2