Cancel current work in PrintDocumentAdatper if printing is cancelled.

Layout and write may take some time during which the user can
cancel printing. Currently we wait for the last operation,
being write or layout, to complete before closing the print
dialog. Now in such a scenario we request a cancellation of
the ongoing operation.

bug:11329523

Change-Id: Ia9d747163cc73509369a86c8b5afc83b7ee54859