FPII-2034: DO NOT MERGE Update libpng to 1.6.20

DO NOT MERGE Update libpng to 1.6.20

BUG:23265085
Change-Id: I2fc2106965c789a54f04412e9c63a0901b0c1e71
(cherry picked from commit 0b39f202aaedd3029e4270d2af7d58ba6634f9cd)
diff --git a/contrib/examples/iccfrompng.c b/contrib/examples/iccfrompng.c
index 386e522..603037e 100644
--- a/contrib/examples/iccfrompng.c
+++ b/contrib/examples/iccfrompng.c
@@ -26,6 +26,10 @@
 
 #include <png.h>
 
+#if defined(PNG_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED) && \
+    defined (PNG_iCCP_SUPPORTED)
+
+
 static int verbose = 1;
 static png_byte no_profile[] = "no profile";
 
@@ -178,3 +182,4 @@
    /* Exit code is true if any extract succeeds */
    return extracted == 0;
 }
+#endif /* READ && STDIO && iCCP */