Fixes a bug where children could have a colored background

Because notifications can have had an override color and could
then become children, the color could stick around.

Test: runtest systemui
Change-Id: Ie89807c41a12b2d4a405c77d6da1c4e4ac78b325
Fixes: 34740139

packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java

@@ -462,6 +462,7 @@ public class ExpandableNotificationRow extends ActivatableNotificationView {
         updateBackgroundForGroupState();
         updateClickAndFocus();
         if (mNotificationParent != null) {
+            setOverrideTintColor(NO_COLOR, 0.0f);
             mNotificationParent.updateBackgroundForGroupState();
         }
         updateIconVisibilities();