Set patchSet field for abandon and restore events

Although both ChangeAbandonEvent, and ChangeRestoreEvent provide
patchSet fields, those fields were not set by the hook handlers. In
accordance with other events, we now set them to the change's current
patch set.

Change-Id: Iaa98322b2c0b0374a1f700d1e6038c4f5bbf0b11
6 files changed