DRAFT Enforce NFSv4

[gmarciani]

DO NOT MERGE YET: This is just a draft, validated on Ubuntu, but facing issues on AL23 and it's missing proper unit tests

Description of changes

Enforce NFSv4-only mode on the NFS server across all supported operating systems.
In particular:

1. Override upstream nfs cookbook defaults to enable NFSv4 and disable NFSv2/NFSv3.
2. Add default['cluster']['nfs']['mask-nfsv2-nfsv3-services'] (default true) to mask rpcbind.service and rpcbind.socket, preventing rpc-statd and nfs-mountd from starting as transitive deps of nfs-server.service. This is done because NFsv4 does not require those services. This is exposed as a Chef attribute so customers who need NFSv2/v3 can set it to false to unmask those services.

Tests

• TODO

References

This change fixes:

1. NFS - Disable V2 and V3 aws-parallelcluster#6622 because we are enforcing now NFSv4-only.
2. chef recipes are forcing lockd to port 32768 which leads to occasional NFS mount failures. aws-parallelcluster#6949 because we are masking the services not required by NFSv4, which were responsible for the intermittent ports collision.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.