Consolidate edit section handling code in ViewPageTarget

Move generation of initial edit summary from setupSaveDialog() to
restoreEditSection().

This allows us to get rid of the properties tracking whether both
halves of the edit section handling had happened, because they're
now in the same method.

Moving setupSaveDialog() down so it runs after restoreEditSection();
this is needed for the communication via this.initialEditSummary
to work correctly.

Change-Id: I06a9c5cf5c752acea8a2ac25d0ffb6ac61cfe986
Merge "Consolidate edit section handling code in ViewPageTarget"