Style variations: Don't display the default if its the only variation (…

…WordPress#63555)

Co-authored-by: scruffian <scruffian@git.wordpress.org>
Co-authored-by: jeryj <jeryj@git.wordpress.org>
Co-authored-by: bgardner <bgardner@git.wordpress.org>

packages/edit-site/src/components/global-styles/style-variations-container.js

@@ -110,6 +110,10 @@ export default function StyleVariationsContainer( { gap = 2 } ) {
 		];
 	}, [ fullStyleVariations, userStyles?.blocks, userStyles?.css ] );
 
+	if ( ! fullStyleVariations || fullStyleVariations?.length < 1 ) {
+		return null;
+	}
+
 	return (
 		<Grid
 			columns={ 2 }