conversation: fix lastevent

Should be considered as new leaf if it is the last non-invalid message.

GitLab: #1627
Change-Id: I34d5e26c085db556a51843f1e74fd30f21ec9f0a

jami-android/libjamiclient/src/main/kotlin/net/jami/model/Conversation.kt

@@ -606,6 +606,8 @@ class Conversation : ConversationHistory {
                     aggregateHistory.add(i, interaction)
                     updatedElementSubject.onNext(Pair(interaction, ElementStatus.ADD))
                     added = true
+                    newLeaf = (i == 0 // True if it is the last non-invalid message.
+                            && aggregateHistory.last().type == Interaction.InteractionType.INVALID)
                     break
                 }
             }