Fix counter when message is updated (#1023)

apps/android/app/src/main/java/chat/simplex/app/model/ChatModel.kt

@@ -163,6 +163,10 @@ class ChatModel(val controller: ChatController) {
       val pItem = chat.chatItems.lastOrNull()
       if (pItem?.id == cItem.id) {
         chats[i] = chat.copy(chatItems = arrayListOf(cItem))
+        if (pItem.isRcvNew && !cItem.isRcvNew) {
+          // status changed from New to Read, update counter
+          decreaseCounterInChat(cInfo.id)
+        }
       }
       res = false
     } else {
@@ -251,6 +255,18 @@ class ChatModel(val controller: ChatController) {
     return markedRead
   }
 
+  private fun decreaseCounterInChat(chatId: ChatId) {
+    val chatIndex = getChatIndex(chatId)
+    if (chatIndex == -1) return
+
+    val chat = chats[chatIndex]
+    chats[chatIndex] = chat.copy(
+      chatStats = chat.chatStats.copy(
+        unreadCount = kotlin.math.max(chat.chatStats.unreadCount - 1, 0),
+      )
+    )
+  }
+
 //  func popChat(_ id: String) {
 //    if let i = getChatIndex(id) {
 //      popChat_(i)