[Template Expressions] fix for incognito getting wrong font style

ui/webui/resources/css/text_defaults_md.css

Index: ui/webui/resources/css/text_defaults_md.css
diff --git a/ui/webui/resources/css/text_defaults_md.css b/ui/webui/resources/css/text_defaults_md.css
index a2b2022667a8bfa2a1e68e4ff115d2ca835a34b5..8900893e2f76f6602c512d240e01fb2cacf21fc4 100644
--- a/ui/webui/resources/css/text_defaults_md.css
+++ b/ui/webui/resources/css/text_defaults_md.css
@@ -18,14 +18,14 @@
 @import url(chrome://resources/css/roboto.css);
 
 html {
-  direction: ${textDirection};
+  direction: $i18n{textDirection};
 }
 
 body {
-  font-family: Roboto, ${fontFamily};
-  font-size: ${fontSize};
+  font-family: Roboto, $i18n{fontFamily};
+  font-size: $i18n{fontSize};
 }
 
 button {
-  font-family: Roboto, ${fontFamily};
+  font-family: Roboto, $i18n{fontFamily};
 }