don't adapt any gray colors to 565

Adapting gray to 565 will add a noticeable purple/green tint.
I'd rather only the 565 images in Gold were tainted with that.

Change-Id: Ib09e92b2f78c6de086345124e9eefeb31bbb5fa8
Reviewed-on: https://skia-review.googlesource.com/147422
Commit-Queue: Mike Klein <mtklein@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
diff --git a/tests/SerializationTest.cpp b/tests/SerializationTest.cpp
index 10838a9..59733fe 100644
--- a/tests/SerializationTest.cpp
+++ b/tests/SerializationTest.cpp
@@ -575,7 +575,7 @@
 
         SkBitmap diffuse = sk_tool_utils::create_checkerboard_bitmap(
                 kTexSize, kTexSize,
-                sk_tool_utils::color_to_565(0x0),
+                0x00000000,
                 sk_tool_utils::color_to_565(0xFF804020),
                 8);