Fix CI: remove onCleared (close() not in published AAR) and revert temperature

- Remove onCleared() override — LlmModule.close() was added in the
  Kotlin conversion (#19211) but the published Maven AAR still ships
  the old Java version without it
- Revert DEFAULT_TEMPERATURE to 0.0 — users can set temperature via
  the UI settings; no need to change the default

Authored with Claude.

Author: psiddh

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

@@ -153,7 +153,7 @@ data class ModuleSettings(
     }
 
     companion object {
-        const val DEFAULT_TEMPERATURE = 0.6
+        const val DEFAULT_TEMPERATURE = 0.0
         val DEFAULT_MODEL = ModelType.LLAMA_3
         val DEFAULT_BACKEND = BackendType.XNNPACK
     }

llm/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/ui/viewmodel/ChatViewModel.kt

@@ -96,13 +96,6 @@ class ChatViewModel(application: Application) : AndroidViewModel(application), L
     private val executor: Executor = Executors.newSingleThreadExecutor()
     private val contentResolver = application.contentResolver
 
-    override fun onCleared() {
-        super.onCleared()
-        module?.close()
-        loadedModules.forEach { (_, m) -> m.close() }
-        loadedModules.clear()
-    }
-
     init {
         // Check for clear chat history flag BEFORE loading saved messages
         val moduleSettings = demoSharedPreferences.getModuleSettings()