chore: switch master branch to use v3.2.0

[andyzhangx]

What type of PR is this?
/kind documentation

What this PR does / why we need it:
chore: switch master branch to use v3.2.0

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

git checkout -b switch-master-3.2.0
sed -i 's/3.1.0/3.2.0/g' Makefile
cd charts/latest/
sed -i 's/3.1.0/3.2.0/g' csi-driver-nfs/Chart.yaml
helm package csi-driver-nfs
git rm csi-driver-nfs-v3.1.0.tgz
git add csi-driver-nfs-v3.2.0.tgz
cd ../../
helm repo index charts --url=https://raw.githubusercontent.com/kubernetes-csi/csi-driver-nfs/master/charts
$git_commit
git push origin switch-master-3.2.0

Does this PR introduce a user-facing change?:

none

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: andyzhangx

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [andyzhangx]

Approvers can indicate their approval by writing /approve in a comment
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[coveralls]

Pull Request Test Coverage Report for Build 1703121037

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 77.716%

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Totals
Change from base Build 1703089671:	0.0%
Covered Lines:	558
Relevant Lines:	718

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💛 - Coveralls