QS: Only allow clicking in the expand button

Also ditch the header BG so the panel can feel like one surface, as
a result need to set some clip bounds on the QSPanel to avoid some
collisions between the header and QS.

Bug: 27881430
Change-Id: Ia78c5b8a7a90bd02b97fa448efa06fc056f624ef
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 12035b9..ed1ad90 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
@@ -225,7 +225,8 @@
             public void onInflated(View v) {
                 mQsContainer = (QSContainer) v.findViewById(R.id.quick_settings_container);
                 mQsContainer.setPanelView(NotificationPanelView.this);
-                mQsContainer.getHeader().setOnClickListener(NotificationPanelView.this);
+                mQsContainer.getHeader().findViewById(R.id.expand_indicator)
+                        .setOnClickListener(NotificationPanelView.this);
             }
         });
         mClockView = (TextView) findViewById(R.id.clock_view);
@@ -1758,7 +1759,7 @@
 
     @Override
     public void onClick(View v) {
-        if (v == mQsContainer.getHeader()) {
+        if (v.getId() == R.id.expand_indicator) {
             onQsExpansionStarted();
             if (mQsExpanded) {
                 flingSettings(0 /* vel */, false /* expand */, null, true /* isClick */);