Alters attempt indicators for a11y

When viewing QLA for multiple attempts, the current attempt is no
longer a link.

Closes CNVS-18363

Test Plan:
  - Confirm that screenreader now identifies the current attempt when
    viewing a QLA recorded set of quiz attempts.

Change-Id: I9d68b2354447ea453c1513b07f6c082d32cfef0b
Reviewed-on: https://gerrit.instructure.com/49784
Tested-by: Jenkins
Reviewed-by: Cameron Sutter <csutter@instructure.com>
QA-Review: Nathan Rogowski <nathan@instructure.com>
Product-Review: Ryan Taylor <rtaylor@instructure.com>

client_apps/canvas_quizzes/apps/events/js/views/session.jsx

@@ -86,16 +86,21 @@ define(function(require) {
 
       if (attempt === this.props.attempt) {
         className += ' ic-AttemptController__Attempt--is-active';
+        return (
+          <div className={className} key={"attempt-"+attempt}>
+            {attempt}
+          </div>
+        )
+      } else {
+        return (
+          <Link
+            to="app"
+            query={query}
+            key={"attempt-"+attempt}
+            className={className}
+            children={attempt} />
+        );
       }
-
-      return (
-        <Link
-          to="app"
-          query={query}
-          key={"attempt-"+attempt}
-          className={className}
-          children={attempt} />
-      );
     }
   });