Fix for bug 5115066 Handler override of toString() hides derived class name

Dynamically getting the class name.

Change-Id: I3140bee67ee2e5a1790e53cf4dfc240d3bb25218

core/java/android/os/Handler.java

@@ -567,7 +567,7 @@ public class Handler {
 
     @Override
     public String toString() {
-        return "Handler{"
+        return "Handler (" + getClass().getName() + ") {"
         + Integer.toHexString(System.identityHashCode(this))
         + "}";
     }