Use std::sort instead of qsort_r wrapper.

The HAVE_(BSD|GNU)_QSORT_R in AndroidConfig.h has never worked, and we
should just be using something standard anyway.

Change-Id: I784d6212f6c890a11c4af2f83d1ce2d279708652
diff --git a/tools/aapt/StringPool.h b/tools/aapt/StringPool.h
index 1b5a7ba..0b26538 100644
--- a/tools/aapt/StringPool.h
+++ b/tools/aapt/StringPool.h
@@ -138,7 +138,14 @@
     const Vector<size_t>* offsetsForString(const String16& val) const;
 
 private:
-    static int config_sort(void* state, const void* lhs, const void* rhs);
+    class ConfigSorter
+    {
+    public:
+        explicit ConfigSorter(const StringPool&);
+        bool operator()(size_t l, size_t r);
+    private:
+        const StringPool& pool;
+    };
 
     const bool                              mUTF8;