title: Reliable way to get role definition
body: <p>What is the best way to get role definition id of the predefined role (like, reader, admin)?</p>
  
  <p>I'm trying to configure a folder to have members have only read permissions. For this I'm removing existing role assignments to members and adding reader role to them. SharePoint REST API requires me to provide role definition id, but I can't find a way to get it reliably.</p>
  
  <p>It seems like I can get it by name <code>_api/web/roledefinitions/getbyname('Read')</code>, but I'm concerned how to handle the case of non-English locale. I would expect it can be searched by type kind <code>_api/web/roledefinitions/getbytypekind(2)</code>, but I can't get it working. It gives me an error <code>Cannot find resource for the request getbytypekind.</code></p>
  
  <p>Also, can default role definition be deleted?</p>