Annotate FIXME for b/200678898

Bug: 200678898
Test: TBD
Change-Id: I433f3187714d5ea19b081ed5e3fe758de0a29ddd

android/arch.go

@@ -934,6 +934,8 @@ func filterArchStruct(field reflect.StructField, prefix string) (bool, reflect.S
 		if len(values) > 0 && values[0] != "path" {
 			panic(fmt.Errorf("unknown tags %q in field %q", values, prefix+field.Name))
 		} else if len(values) == 1 {
+			// FIXME(b/200678898): This assumes that the only tag type when there's
+			// `android:"arch_variant"` is `android` itself and thus clobbers others
 			field.Tag = reflect.StructTag(`android:"` + strings.Join(values, ",") + `"`)
 		} else {
 			field.Tag = ``