Clear state when ProgressMessageCtrl. is canceled

Otherwise the following can happen:
- The progressController is _not_ running and we are running through
  an update.
- Then onUpdateCompleted is called which cancels the not running
  progressController. This then reset whatever state was previously
  stored as mPreviousState leaving the PrintActivity in a weird state.

Fixes: 27945565
Change-Id: Id46b8853ba634634198a74921c8a1790c435678c