Brightness mirror should use QS theme

Always re-inflate the brightness mirror using the
quick settings theme. It's a child of the status
bar window and needs the theme to be explicit.

Change-Id: I342cda303feba4fa9c48afc0f119d8b74657dcd7
Fixes: 68366763
Test: Look at brightness slider using a dark wallpaper
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
index 86a8f41..fff6abe 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
@@ -330,7 +330,7 @@
         }
     }
 
-    public void onOverlayChanged() {
+    public void onThemeChanged() {
         // Re-inflate the status view group.
         int index = indexOfChild(mKeyguardStatusView);
         removeView(mKeyguardStatusView);