Header content is only used by DataRecordPresenters when the FieldLayout's LabelLocationResolved property returns 'SeparateHeader'.
Note: Not all views support separate headers, e.g. CarouselView. The FieldLayout's FieldLayout.HasSeparateHeader returns true if a separate header has been generated.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2