title: ASP.Net Core with EF Core and CosmosDB - IdentityRole issue
body: <p>I am trying to migrate my asp.net core application from using Azure SQL database to use CosmosDB database.</p>
  <p>Facing an issue when trying to create collections with the following error messages:</p>
  <blockquote>
  <p>System.InvalidOperationException: 'The entity type 'IdentityRole' has
  property 'ConcurrencyStamp' as its concurrency token, but only '_etag'
  is supported. Consider using 'EntityTypeBuilder.UseETagConcurrency'.'</p>
  </blockquote>
  <p>I have tried these changes, none of them solve the issue.</p>
  <ol>
  <li>I added <code>UseETagConcurrency</code> when building the model
  <code>builder.Entity&lt;IdentityRole&gt;().ToContainer(&quot;Roles&quot;).UseETagConcurrency();</code></li>
  <li>I create new derived class from <code>IdentityRole</code>, added <code>_etag</code>
  property to <code>Role</code> model</li>
  </ol>
  <p>Any ideas on how to resolve this issue?</p>
  <p>Thank you for your assistance.</p>