Default statistic custom field
Introduction
In Portal statistic, when user add new chart, statistic filter will
displays default 5 custom string fields CustomVarCharField1 to
CustomVarCharField5 , you can customize them by your own custom
string fields.

Customization
Create an override which overrides sub process
createDefaultStatisticCustomField() in PortalKit. This sub process
return a list of custom string fields. Follow instruction to create
default custom fields.
