Fix incorrent page range parsing when custom print options used.

We have APIs for a print service to declare an activity with custom
print options. In this activity the service can add custom properties
as well as change the standard ones such as pages to print. The ranges
of selected pages from the custom activity was incorrectly parsed
resulting in an off by one error in what is shown to the user and as a
result getting an exception when trying to print.

bug:11719051

Change-Id: Id04c94608178895f1d47381a63133f0eba7645e1