fix nfs-provisioner for appc and sdnc

fix nfs-provisioner for appc and sdnc

change in common/mysql/templates/pvc.yaml to allow pvc use
when persistence is required
change in common/mysql/templates/storageclass.yaml to be
led by the disableNfsprovisioner variable
change in appc/values to default the disableNfsprovisioner
to false as it is in sdnc

changing the default disableNfsprovisioner to true for both appc and sdnc

changing the stateful set avoid volumeclaimtemplates.
When used in helm, the volumeclaimtemplates is causing pvc to be left
after the helm delete --purge. I guess this is due to the fact the pvc
are not directly created by the helm install by indirectly by kubernetes

Now the tests are working in both cases (nfsprovisioner disabled or not)
The only piece remaining after a helm delete is pv in released state
in case we are using nfsprovisioner. That makes sense again because this
are objects created by the provisioner and not by helm.

removed some leftover

Issue-ID: OOM-787
Change-Id: Ieb1f1c482217aeb1b89be39a437bb891a299db71
Signed-off-by: Jerome Doucerain <jerome.doucerain@bell.ca>