Introduce AmbientState for StackScroller.

AmbientState is a global state for the algorithm of the
StackScroller. Dimmed and which child is activated was moved
into this state. Further, scale and dimmed is also a
StackScrollState and animated in StackStateAnimator.

Change-Id: Ia68131cee62b2e0005f55ea6dc400d149ec15278
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/tv/TvStatusBar.java b/packages/SystemUI/src/com/android/systemui/statusbar/tv/TvStatusBar.java
index d6a8885..9006c9a 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/tv/TvStatusBar.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/tv/TvStatusBar.java
@@ -150,4 +150,11 @@
     protected void refreshLayout(int layoutDirection) {
     }
 
+    @Override
+    public void onActivated(View view) {
+    }
+
+    @Override
+    public void onActivationReset(View view) {
+    }
 }