fix: don't enable expiring messages in not approvedMe conversations

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/menus/ConversationMenuHelper.kt

@@ -58,7 +58,7 @@ object ConversationMenuHelper {
         // Base menu (options that should always be present)
         inflater.inflate(R.menu.menu_conversation, menu)
         // Expiring messages
-        if (!isOpenGroup) {
+        if (!isOpenGroup && thread.hasApprovedMe()) {
             if (thread.expireMessages > 0) {
                 inflater.inflate(R.menu.menu_conversation_expiration_on, menu)
                 val item = menu.findItem(R.id.menu_expiring_messages)