Fixes LE Sysui update to use new instead of old

Fixes a bug in Lifetime Extension Refactor where we were using the old
notification to post the update to system UI, instea dof the new
notification. In the case that the app cancels the notification, this
doesn't matter, because the old notification and the new will be the
same. In the case that the app UPDATES the notification, though, we want
SystemUI to reflect the state of the new notification, not the old one.
We have to check the old one for the presence of the flag (because apps
can't post notifications with the LE flag enabled, it gets removed in
fix notification), but we want to check the _contents_ of the new one
for the update, so that any changes the app made in response to the
direct reply are reflected.

Bug: 333131289
Test: atest NotificationManagerServiceTest, atest
NotificationListenersTest
Flag: ACONFIG android.app.lifetime_extension_refactor STAGING

Change-Id: Ic16eaa5815bddff9a3ddde7930d73508da9f61b4