title: Azure DevOps pipeline asks to run 'az login' to setup account
body: <p>I've successfully run pipeline with step below to push docker image to registry. When I try to re-run it gives an <strong>ERROR</strong>: <em>Please run 'az login' to setup account</em></p>
  
  <pre><code>- bash: az acr helm push -n $(registryName) -u $(registryLogin) -p $(registryPassword) $(build.artifactStagingDirectory)/$(projectName)-$(build.buildId).tgz
    displayName: 'az acr helm push'
    condition: and(succeeded(), eq(variables['build.sourceBranch'], 'refs/heads/master'))
  </code></pre>
  
  <p>The step is seen in the logs as below so shouldn't require any additional information (it works when run from command line on my local machine)</p>
  
  <pre><code>az acr helm push -n acrname -u acruser -p password /home/vsts/work/1/a/chart.tgz
  </code></pre>