Another copy/paste mistake

Author: huydhn

examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/LlmBenchmarkRunner.java

@@ -37,7 +37,7 @@ protected void onCreate(Bundle savedInstanceState) {
     Intent intent = getIntent();
 
     modelDir = new File(intent.getStringExtra("model_dir"));
-    File model = Arrays.stream(directory.listFiles())
+    File model = Arrays.stream(modelDir.listFiles())
             .filter(file -> file.getName().endsWith(".pte"))
             .findFirst();
     String tokenizerPath = intent.getStringExtra("tokenizer_path");