Always initialize AsyncTask on the main thread.

Change-Id: I039e5d6cb7157a0c8873e0d29161daf1cbda5577
diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index 9807b89..3c5f53a 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -4413,7 +4413,7 @@
         });
     }
 
-    public static final ActivityThread systemMain() {
+    public static ActivityThread systemMain() {
         HardwareRenderer.disable(true);
         ActivityThread thread = new ActivityThread();
         thread.attach(true);
@@ -4454,6 +4454,8 @@
         ActivityThread thread = new ActivityThread();
         thread.attach(false);
 
+        AsyncTask.init();
+
         if (false) {
             Looper.myLooper().setMessageLogging(new
                     LogPrinter(Log.DEBUG, "ActivityThread"));