Always supply a color space (sRGB for now) with F16

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2177193004

Review-Url: https://codereview.chromium.org/2177193004
diff --git a/tools/skiaserve/Request.cpp b/tools/skiaserve/Request.cpp
index 44e5ddf..f61ed55 100644
--- a/tools/skiaserve/Request.cpp
+++ b/tools/skiaserve/Request.cpp
@@ -167,7 +167,7 @@
 ColorAndProfile ColorModes[] = {
     { kN32_SkColorType,      false, false },
     { kN32_SkColorType,       true, true },
-    { kRGBA_F16_SkColorType, false, true },
+    { kRGBA_F16_SkColorType,  true, true },
 };
 
 }