fix(material/core): remove legacy theming in devapp

Author: andrewseguin

src/dev-app/theme.scss

@@ -45,7 +45,17 @@ $candy-app-theme: mat.define-light-theme((
   $dark-primary: mat.define-palette(mat.$blue-grey-palette);
   $dark-accent: mat.define-palette(mat.$amber-palette, A200, A100, A400);
   $dark-warn: mat.define-palette(mat.$deep-orange-palette);
-  $dark-colors: mat.define-dark-theme($dark-primary, $dark-accent, $dark-warn);
+  $dark-colors: mat.define-dark-theme(
+      (
+        color: (
+          primary: $dark-primary,
+          accent: $dark-accent,
+          warn: $dark-warn
+        ),
+        density: 0,
+        typography: mat.define-typography-config(),
+      )
+  );
 
   // Include the dark theme color styles.
   @include mat.all-component-colors($dark-colors);
@@ -55,7 +65,7 @@ $candy-app-theme: mat.define-light-theme((
 
   // Include the dark theme colors for focus indicators.
   &.demo-strong-focus {
-    @include mat.strong-focus-indicators-theme($dark-colors);
+    @include mat.strong-focus-indicators-color($dark-colors);
   }
 }