Now it is possible to restore status of abandoned changes to 'NEW'.
It helps in a situation when a change has been abandoned accidently.
Bug: issue 312
Change-Id: Iba61dcf82a9b5ee5b78cd529b041f92a042a9611
[cherry-picked from 3200245774]
Change-Id: Icc6dddb63689250c869189639af0d72ed8837336