fix: app-css-loader to look for platform specific app s?css files too

packages/webpack5/src/loaders/app-css-loader/index.ts

@@ -4,13 +4,16 @@ import { dedent } from 'ts-dedent';
  * This loader tries to load an `app.scss` or and `app.css` relative to the main entry
  */
 export default function loader(content: string, map: any) {
+	const { platform } = this.getOptions();
 	const callback = this.async();
 	const resolve = this.getResolve({
-		extensions: ['.scss', '.css'],
+		extensions: [`.${platform}.scss`, `.${platform}.css`, '.scss', '.css'],
 	});
 
 	resolve(this.context, './app', (err, res) => {
 		if (err || !res) {
+			// if we ran into an error or there's no css file found, we just return
+			// original content and not append any additional imports.
 			return callback(null, content, map);
 		}