chore(demo): simplify Android and iOS clean scripts

Author: fadi-george

examples/demo/package.json

@@ -8,8 +8,8 @@
     "preios": "bun run setup",
     "android": "bash ../run-android.sh",
     "ios": "bash ../run-ios.sh",
-    "clean:android": "cd android && ./gradlew clean && cd ..",
-    "clean:ios": "cd ios && xcodebuild clean && cd ..",
+    "clean:android": "rm -rf android/app/build android/app/.cxx android/build",
+    "clean:ios": "rm -rf ios/build ios/Pods",
     "lint": "eslint .",
     "start": "react-native start",
     "test": "jest"