The MIME type should match the extension on the name of the attachment data provided. It can be any string provided. However, for
applications in the ArcGIS platform to correctly open the attachment it must match the attached document. For example, to attach
a png image file named 'FireTruck09.png', the ContentType would be: 'image/png'.
Requirements
Target Platforms: Windows 10, Windows 8.1, Windows 7