title: What is the Regex for cloudformation IAM policy name
body: <p>I am trying define a parameter for the IAM role name. Here's my parameter</p>
  
  <pre><code>         Type: String
           AllowedPattern: "arn:aws:iam::*$"
           ConstraintDescription: Must be an IAM policy ARN.
  </code></pre>
  
  <p>The IAM policy name is of the format - <code>arn:aws:iam::AccountNumber:policy/staging_test</code></p>
  
  <p>Here's the error I am getting 
  <code>Parameter EnvDynamoDbPolicy failed to satisfy constraint:</code></p>