vcl: work around missing std::fmax() on Android

Change-Id: Iaa4e6aa84c163f2ec5541f233cf7593c0a501b5e

vcl/unx/generic/gdi/cairotextrender.cxx

@@ -44,6 +44,16 @@
 #include <cairo-ft.h>
 #include "CommonSalLayout.hxx"
 
+#ifdef ANDROID
+namespace std
+{
+double fmax(double x, double y)
+{
+    return ::fmax(x, y);
+}
+}
+#endif
+
 namespace {
 
 typedef struct FT_FaceRec_* FT_Face;