The primitive ChangeNovaServiceState allows us to change the state of
the nova-compute by calling nova api. The state of a nova-compute can
be ENABLED or DISABLED, however in the current implementation we use
OFFLINE and ONLINE.
Update the code to use ENABLED or DISABLED.
Change-Id: If3d9726bc5ae980b66c7fd4c5b7986f89d8bc690
Closes-Bug: #1523891