Merge pull request #14118 from IgniteUI/didimmova/accordion-sample

chore(accordion-sample): remove overwritten theme values

Author: kdinev

src/app/accordion/accordion.sample.scss

@@ -1,4 +0,0 @@
-igx-expansion-panel {
-    --header-background: hsl(var(--ig-gray-300));
-    --body-background: hsl(var(--ig-gray-300));
-}