Fix engagement started on the chat screen

When the chat screen opens with the secure conversation state, resubscribe to the engagement streams. This solves the upgrade to chat state issue.

MOB-3888

widgetssdk/src/main/java/com/glia/widgets/chat/controller/ChatController.kt

@@ -146,6 +146,7 @@ internal class ChatController(
 
     private val disposable = CompositeDisposable()
     private val mediaUpgradeDisposable = CompositeDisposable()
+    private val engagementDisposable = CompositeDisposable()
 
     private val sendMessageCallback: GliaSendMessageUseCase.Listener = object : GliaSendMessageUseCase.Listener {
         override fun messageSent(message: VisitorMessage?) {
@@ -258,6 +259,10 @@ internal class ChatController(
         emitViewState { chatState.initChat().setSecureMessagingState() }
         ensureSecureMessagingAvailable()
         observeTopBannerUseCase()
+
+        // When the chat screen opens with the secure conversation state, resubscribe to the engagement streams.
+        // This solves the upgrade to chat state issue.
+        subscribeToEngagement()
     }
 
     private fun observeTopBannerUseCase() {
@@ -287,9 +292,10 @@ internal class ChatController(
     }
 
     private fun subscribeToEngagement() {
-        engagementStateUseCase().unSafeSubscribe(::onEngagementStateChanged)
-        operatorMediaUseCase().unSafeSubscribe(::onNewOperatorMediaState)
-        onOperatorTypingUseCase().unSafeSubscribe(::onOperatorTyping)
+        engagementDisposable.clear()
+        engagementDisposable.add(engagementStateUseCase().subscribe(::onEngagementStateChanged))
+        engagementDisposable.add(operatorMediaUseCase().subscribe(::onNewOperatorMediaState))
+        engagementDisposable.add(onOperatorTypingUseCase().subscribe(::onOperatorTyping))
     }
 
     private fun ensureSecureMessagingAvailable() {
@@ -376,6 +382,7 @@ internal class ChatController(
         backClickedListener = null
         if (!retain) {
             disposable.clear()
+            engagementDisposable.clear()
             timerStatusListener = null
             callTimer.clear()
             minimizeHandler.clear()