### Summary The Intercom Android SDK crashes with a NullPointerException when users tap on "recent messages" or try to access previous chat conversations. The crash occurs in the TopAppBarUiState constructor when it receives a null subtitle parameter. ### Environment SDK Version: intercom_flutter: ^9.4.6 Platform: Android Flutter Version: 3.6.0+ Target SDK: 34 Min SDK: 24 ### Steps to Reproduce Initialize Intercom in the app Open Intercom messenger (this works fine) Create message ("test" for example) and go back to main page Tap on "recent messages" or try to access previous chat conversations App crashes immediately with the stack trace below ### Expected Behavior Users should be able to access their previous chat conversations and recent messages without the app crashing. ### Actual Behavior App crashes with NullPointerException when trying to load conversation history, specifically when the SDK attempts to create the top app bar state for the conversation view. ### Stack Trace ``` E/AndroidRuntime(27242): FATAL EXCEPTION: main java.lang.NullPointerException: Parameter specified as non-null is null: method io.intercom.android.sdk.m5.conversation.states.TopAppBarUiState.<init>, parameter subtitle E/AndroidRuntime(27242): at io.intercom.android.sdk.m5.conversation.states.TopAppBarUiState.<init>(Unknown Source:7) E/AndroidRuntime(27242): at io.intercom.android.sdk.m5.conversation.reducers.HeaderReducerKt.reduceTopAppBarUiState(HeaderReducer.kt:45) E/AndroidRuntime(27242): at io.intercom.android.sdk.m5.conversation.reducers.ConversationReducer.computeUiState$intercom_sdk_base_release(ConversationReducer.kt:68) E/AndroidRuntime(27242): at io.intercom.android.sdk.m5.conversation.ConversationViewModel$special$$inlined$map$1$2.emit(Emitters.kt:220) E/AndroidRuntime(27242): at kotlinx.coroutines.flow.StateFlowImpl.collect(StateFlow.kt:392) E/AndroidRuntime(27242): at kotlinx.coroutines.flow.StateFlowImpl$collect$1.invokeSuspend(Unknown Source:15) E/AndroidRuntime(27242): at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) E/AndroidRuntime(27242): at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:104) E/AndroidRuntime(27242): at android.os.Handler.handleCallback(Handler.java:1087) E/AndroidRuntime(27242): at android.os.Handler.dispatchMessage(Handler.java:125) E/AndroidRuntime(27242): at android.os.Looper.dispatchMessage(Looper.java:333) E/AndroidRuntime(27242): at android.os.Looper.loopOnce(Looper.java:263) E/AndroidRuntime(27242): at android.os.Looper.loop(Looper.java:367) E/AndroidRuntime(27242): at android.app.ActivityThread.main(ActivityThread.java:9230) E/AndroidRuntime(27242): at java.lang.reflect.Method.invoke(Native Method) E/AndroidRuntime(27242): at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:593) E/AndroidRuntime(27242): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:929) ```