system/core: Make Thread::run threadName argument required

Bug: 27557176
Change-Id: Iae83a1e5489c86c2858fc8481f246b8480f0eec4
diff --git a/include/utils/Thread.h b/include/utils/Thread.h
index 1532b7e..3792db7 100644
--- a/include/utils/Thread.h
+++ b/include/utils/Thread.h
@@ -45,7 +45,7 @@
     virtual             ~Thread();
 
     // Start the thread in threadLoop() which needs to be implemented.
-    virtual status_t    run(    const char* name = 0,
+    virtual status_t    run(    const char* name,
                                 int32_t priority = PRIORITY_DEFAULT,
                                 size_t stack = 0);