CloudLogging Policy - Dynamic module

[phertzog]

I have created a Sharedflow that contains a CloudLogging policy like described below.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<MessageLogging continueOnError="false" enabled="true" name="ML-CloudLogging">

  <DisplayName>ML-CloudLogging</DisplayName>

  <CloudLogging>

    <LogName>projects/{organization.name}/logs/apigee</LogName>

    <Message contentType="application/json">{

    "verb": "{request.verb}",

    "response_code": "{response.status.code}"

    }</Message>

    <Labels>

      <Label>

        <Key>Proxy</Key>

        <Value>{apiproxy.name}</Value>

      </Label>

      <Label>

        <Key>Environment</Key>

        <Value>{environment.name}</Value>

      </Label>

    </Labels>

  </CloudLogging>

</MessageLogging>

The logging works as expected but the value for the label is not extrapolated. 

Is there a way to dynamicaly set the value of the label?

Regards