Add reference to isolated hosts-iso image restrict

Havana added a new parameter, which is already documented,
that alters the IsolatedHostsSchedule so that IsolatedHosts
can run only Isolated images. This patch adds a sentence
explaining this.

Change-Id: I26d1fe3d3daab4df944f0d9f83e940f953fe1c81
Closes-Bug: 1208526
Unlock/Lock can now be user actions

Havana allowed lock & unlock to be performed by
users, in addition to admins. This updates the policy.json
example to be in line with the sample

Change-Id: I6a81d1890173672149293ee41bfa9e553cfb9e04
Closes-Bug: 1206724
Merge "Add reference to isolated hosts-iso image restrict"
Merge "Unlock/Lock can now be user actions"