docs: Fix broken link in Volley training

am: 05dd9d2c

* commit '05dd9d2c':
  docs: Fix broken link in Volley training

Change-Id: Ia20dd9788d855129033c82e2161e01dc382d85b7

docs/html/training/volley/request.jd

@@ -38,7 +38,7 @@ This lesson describes how to use the common request types that Volley supports:<
 
 <p>If your expected response is one of these types, you probably won't have to implement a
 custom request. This lesson describes how to use these standard request types. For
-information on how to implement your own custom request, see <a href="requests-custom.html">
+information on how to implement your own custom request, see <a href="request-custom.html">
 Implementing a Custom Request</a>.</p>