Host level replication capability was added to the NetApp
cDOT Block and File drivers through
I87b92e76d0d5022e9be610b9e237b89417309c05.
However, the replication capability was not being reported
at the pool level.
Add the field at pool level allowing for compatibility with
volume types that may include the `replication_enabled`
extra-spec.
Change-Id: Ic735a527c609166884668c84c589da521769500b
Closes-Bug: #1615451
