Fixing serialization of grid-auto-flow

This CL fixes a serialization of grid-auto-flow issue where the word
'row' was being included even though it isn't necessary. The tests
grid-auto-flow-computed.html and grid-auto-flow-valid.html are fixed,
while the expectations of wpt and fast tests are updated or modified to
add new passes.

Bug: 1156390
Change-Id: If91100c3eff7b6cd4caf349114afb0fec71e9e98
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3179598
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Kurt Catti-Schmidt <kschmi@microsoft.com>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Commit-Queue: Ana Sollano Kim <ansollan@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#925295}

css/css-typed-om/the-stylepropertymap/properties/grid-auto-flow.html

@@ -19,7 +19,7 @@
 ]);
 
 runUnsupportedPropertyTests('grid-auto-flow', [
-  'row dense', 'column dense',
+  'column dense',
 ]);
 
 </script>