The unique SDK App Id.
This property must be set to a universally unique Id created for a specific installation of the app on a consumer device. The app is responsible for generating and storing the SDKAppId for each installation or update. This property must be set before calling GetAuthRequest.
The value assigned here must be 36 characters and be in the format defined in IETF RFC 4122. For example: 8a880dc0-d2d2-4067-bcb1-b08d1690b26e.