Backport of Datadog Unix Socket Path Custom Path fix into release/1.4.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #3635 to be assessed for backporting due to the inclusion of the label backport/1.4.x.

The below text is copied from the body of the original PR.

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Changes proposed in this PR

Initial integration hard-coded Unix Domain Socket hostPath for the consul-server statefulset, making the Helm override global.metrics.datadog.dogstatsd.dogstatsdAddr not useful if users wanted/needed a custom UDS socket path beyond the default value of /var/run/datadog.

# server-statefulset.yaml
...
        volumes:
            - name: dsdsocket
              hostPath:
                  path: /var/run/datadog
                  type: DirectoryOrCreate

This PR updates this to use the helm override as intended for custom UDS paths

# server-statefulset.yaml
...
        volumes:
            - name: dsdsocket
              hostPath:
                  path: {{ dir .Values.global.metrics.datadog.dogstatsd.dogstatsdAddr | trimAll "\"" }}
                  type: DirectoryOrCreate

How I've tested this PR

Updated server-statefulset.bats with the following tests for default and non-default paths:

• "server/StatefulSet: datadog unix socket path name rendering for hostPath volume and volumeMount using default"
• "server/StatefulSet: datadog unix socket path name rendering for hostPath volume and volumeMount using non default"

Tested locally running a k3d cluster with latest build. Repo

How I expect reviewers to test this PR

👀 Acceptance test results

Checklist

• Tests added
• CHANGELOG entry added

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Overview of commits

• 7512f0e - a64ccf2 - bf638d2