fix(material/toolbar): Allow typography mixin to consume 2018 style configs

See angular#21059 for context.

Author: mmalerba

src/material/toolbar/_toolbar-theme.scss

@@ -2,6 +2,7 @@
 @import '../core/style/variables';
 @import '../core/theming/palette';
 @import '../core/theming/theming';
+@import '../core/typography/typography';
 @import '../core/typography/typography-utils';
 @import './toolbar-variables';
 
@@ -68,6 +69,7 @@
 }
 
 @mixin mat-toolbar-typography($config-or-theme) {
+  $config: mat-private-typography-normalized-config(mat-get-typography-config($config-or-theme));
   $config: mat-get-typography-config($config-or-theme);
   .mat-toolbar,
   .mat-toolbar h1,