title: Passing a json-string command arg in a YAML file
body: <p>I'm trying to run a command which changes kubernetes cronjob image value as described <a href="https://github.com/kubernetes/kubernetes/issues/57393#issuecomment-352707423" rel="nofollow noreferrer">here</a>.
  But instead of typing this command to cmd i'm trying to run it via Container Registry's build trigger.</p>
  
  <p>I tried ' and \ as escape chars. </p>
  
  <pre><code>  steps:
       - name: 'gcr.io/cloud-builders/kubectl'
        args: [
        "patch",
         "cronjob",
         "cron-history-orders",
         "--type=json",
        "-p=[{'"op'":'"replace'",'"path'":'"/spec/jobTemplate/spec/template/spec/containers/0/image'",'"value'":'"python:3.5'"}]"
         ]
        env:  ['CLOUDSDK_COMPUTE_ZONE=europe-west3-c','CLOUDSDK_CONTAINER_CLUSTER=xxx-prod']
  </code></pre>
  
  <p>or when I try </p>
  
  <pre><code>   "-p='[{\"op\":\"replace\", \"path\": \"/spec/jobTemplate/spec/template/spec/containers/0/image\", \"value\":\"python:3.5\"}]'"
  </code></pre>
  
  <p>or    </p>
  
  <pre><code>  "-p='[{'op':'replace','path':'/spec/jobTemplate/spec/template/spec/containers/0/image','value':'python:3.5'}]'"
  </code></pre>
  
  <p>I get <code>error loading template: json: cannot unmarshal object into Go value of type []json.RawMessage</code></p>