title: A PolicyStatement used in an identity-based policy cannot specify any IAM principals error
body: <pre><code>    let servicePrincipal: any = new iam.ServicePrincipal(&quot;lambda.amazonaws.com&quot;);
  
      let policyDoc = new iam.PolicyDocument({
        statements: [
          new iam.PolicyStatement({
            actions: [&quot;sts:AssumeRole&quot;],
            principals: [servicePrincipal],
            effect: iam.Effect.ALLOW,
            resources: [&quot;arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole&quot;],
            sid: &quot;&quot;
          })
        ],
      });
  
      let accessRole: any = new iam.Role(this, 'git-access-role', {
        assumedBy: servicePrincipal,
        inlinePolicies: { policyDoc }
      });
  </code></pre>
  <p>I'm creating a cdk lambda with a role that has AWSLambdaBasicExecutionRole but I get an error saying</p>
  <pre><code>A PolicyStatement used in an identity-based policy cannot specify any IAM principals
  </code></pre>
  <p>not quite sure...what does it mean and what should I do?</p>