DLPX-81551 nfs-utils 2.6.1 - update initial NFS configuration

[don-brady]

Context:

Part of move to nfs-utils 2.6.1 (CP-7193).

Updated the ansible-roles that establish the initial nfs configuration.
virtualization:
live-build/misc/ansible-roles/appliance-build.virtualization-common/tasks/main.yml

dcenter:
live-build/misc/ansible-roles/appliance-build.dcenter/tasks/main.yml

Testing

ab-pre-push
http://selfservice.jenkins.delphix.com/job/appliance-build-orchestrator-pre-push/2232/ (dcenter variant)
http://selfservice.jenkins.delphix.com/job/appliance-build-orchestrator-pre-push/2233/ (internal dev variant)

Manually tested the dcenter role on a dcenter VM image

Notes To Reviewers:

Note for dcenter we want to use the same configuration settings as is used in the appliance.

CP-7193 Deployment Plan:

1. This and dlpx-app-gate change (DLPX-81550) land first.
2. Then the nfs-utils change (DLPX-81548 ) can land.
3. Finally we can land the delphix-platform change (DLPX-81549)