Whitelist 'protect' and 'unprotect' core actions

Some actions from core, like protect and unprotect, are viable
actions to perform against a flow board.  Whitelist such actions
from being taken over by Flow.

Bug: 60301
Change-Id: Id80c989b2883c8046c5fd8267b05db636461a8c3
Merge "Whitelist 'protect' and 'unprotect' core actions"