[stable/buildkite] Fix newline issue when using extraEnv

[bshelton229]

I was seeing a missing newline when using extraEnv causing:

          env:
            # BUILDKITE AGENT ENV VARS
            - name: BUILDKITE_AGENT_TOKEN
              valueFrom:
                secretKeyRef:
                  name: RELEASE-NAME-buildkite
                  key: agent-token
            - name: BUILDKITE_AGENT_META_DATA
              value: "role=agent,queue=bryan-testing"
            # EXTRA BUILDKITE AGENT ENV VARS            - name: HELLO
              value: world

Thanks!

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[bshelton229]

/assign @mattfarina

[lachie83]

/ok-to-test

[timstoop]

/lgtm

[unguiculus]

/lgtm

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[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: bshelton229, timstoop, unguiculus

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