Fix missing reason param in ChangeRestoredEvent

'reason' param in ChangeRestoredEvent got accidentally dropped
 by Id429d8cd9e626d88c1f81954e6b37488896f9b90.

This CL adds the 'reason' param back.

Change-Id: I0dbd47ef3ab737b1be8bd2c4707dbf1a8f5b57cf
1 file changed