Fix "select model" message showing even when model is already loaded

Co-authored-by: kirklandsign <107070759+kirklandsign@users.noreply.github.com>

Author: Copilot

llm/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/MainActivity.java

@@ -381,11 +381,13 @@ protected void onResume() {
           // If users change the model file, but not pressing loadModelButton, we won't load the new
           // model
           checkForUpdateAndReloadModel(updatedSettingsFields);
-        } else {
+        } else if (mModule == null) {
+          // Only ask user to select model if no model is currently loaded
           askUserToSelectModel();
         }
       }
-    } else {
+    } else if (mModule == null) {
+      // Only ask user to select model if no model is currently loaded
       askUserToSelectModel();
     }
   }