style: Enable CSS column-span in UA stylesheet, and update test expec…

…tations.

We use "column-span: all" in ua.css in Part 3. To be able to flip the pref
in individual wpt tests, we need column-span to be always enabled
in UA stylesheets.

Differential Revision: https://phabricator.services.mozilla.com/D5212

components/style/properties/longhands/column.mako.rs

@@ -65,13 +65,15 @@ ${helpers.predefined_type(
     spec="https://drafts.csswg.org/css-multicol/#propdef-column-rule-color",
 )}
 
+// FIXME: Remove enabled_in="ua" once column-span is enabled on nightly (bug 1423383).
 ${helpers.single_keyword(
     "column-span",
     "none all",
     products="gecko",
     animation_value_type="discrete",
     gecko_enum_prefix="StyleColumnSpan",
     gecko_pref="layout.css.column-span.enabled",
+    enabled_in="ua",
     spec="https://drafts.csswg.org/css-multicol/#propdef-column-span",
     extra_prefixes="moz:layout.css.column-span.enabled",
 )}