String16.cpp rm unused utils/Debug.h

Change-Id: Ie7e3695770f20be33738a0f0a868cc914248d91a
diff --git a/libutils/String16.cpp b/libutils/String16.cpp
index b09b728..3bdc349 100644
--- a/libutils/String16.cpp
+++ b/libutils/String16.cpp
@@ -16,7 +16,6 @@
 
 #include <utils/String16.h>
 
-#include <utils/Debug.h>
 #include <utils/Log.h>
 #include <utils/Unicode.h>
 #include <utils/String8.h>