Add missing F16 case to reverse pixel config conversion

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1884753002

Review URL: https://codereview.chromium.org/1884753002

src/gpu/SkGr.cpp

@@ -467,6 +467,9 @@ bool GrPixelConfig2ColorAndProfileType(GrPixelConfig config, SkColorType* ctOut,
             ct = kBGRA_8888_SkColorType;
             pt = kSRGB_SkColorProfileType;
             break;
+        case kRGBA_half_GrPixelConfig:
+            ct = kRGBA_F16_SkColorType;
+            break;
         default:
             return false;
     }