Microsoft.UI.Xaml v2.1.190405004

This is the official release of the WinUI 2.1 package!

https://www.nuget.org/packages/Microsoft.UI.Xaml/2.1.190405004

Release notes: https://docs.microsoft.com/en-us/uwp/toolkits/winui/release-notes/winui-2.1

Notable bug fixes:

• Fix for text flow issue in first uniform grid item (f306854b by ranjeshj, pr #492)
• TeachingTip Keyboarding and Accessibility (3dd44763 by StephenLPeters, pr #469)
• Provide API to enable compact in app level. (0cb28b4c by licanhua, pr #456)
• Build the manifest activatable class entries for the framework package from the winmd instead of test app manifest (3d8fa360 by ranjeshj, pr #441)