Fix missing HUN icon after direct reply

Flag: ACONFIG com.android.systemui.notifications_icon_container_refactor DEVELOPMENT
Fixes: 316797741
Test: atest SystemUITests
Test: manual
  1. Post MessagingStyle notif with MAX priority
  2. Direct reply to notification while it is still Heads Up
  3. Verify status bar looks correct after reply is sent
Change-Id: Ia96b593a939ef4768a1f91bb8eecc630520b6f70