Use multiple async tasks.

Change-Id: If6be431a4f9443eaaf4478bae57c29f77f558b91
diff --git a/samples/ApiDemos/src/com/example/android/apis/app/LoaderThrottle.java b/samples/ApiDemos/src/com/example/android/apis/app/LoaderThrottle.java
index fb69ff6..1c4c839 100644
--- a/samples/ApiDemos/src/com/example/android/apis/app/LoaderThrottle.java
+++ b/samples/ApiDemos/src/com/example/android/apis/app/LoaderThrottle.java
@@ -449,7 +449,8 @@
                             return null;
                         }
                     };
-                    mPopulatingTask.execute((Void[])null);
+                    mPopulatingTask.executeOnExecutor(
+                            AsyncTask.THREAD_POOL_EXECUTOR, (Void[])null);
                     return true;
 
                 case CLEAR_ID: