If notifications can scroll at all, allow scroll up to status bar

Fixes: 190748504

Test: 1 notif => no scroll
Test: 2 notifs, just enough to scroll => scrolls up to status bar
Test: no scrollRange regressions with
- enough notifs to scroll up and cover qs completely
- inline reply to show IME

Change-Id: I8d2215d841b52df21a45293a23e7aff09b39c7ae

packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayout.java

@@ -2073,6 +2073,9 @@ public class NotificationStackScrollLayout extends ViewGroup implements Dumpable
         int scrollRange = Math.max(0, contentHeight - mMaxLayoutHeight);
         int imeInset = getImeInset();
         scrollRange += Math.min(imeInset, Math.max(0, contentHeight - (getHeight() - imeInset)));
+        if (scrollRange > 0) {
+            scrollRange = Math.max(getScrollAmountToScrollBoundary(), scrollRange);
+        }
         return scrollRange;
     }