Disabling alpha layer on some views

Change-Id: Ide1d5951ea80080f8fea8f32a76487b646b4f958
(cherry picked from commit 2020b20cd9)

src/com/android/launcher3/allapps/FloatingHeaderView.java

@@ -237,6 +237,11 @@ public class FloatingHeaderView extends LinearLayout implements
     public boolean hasVisibleContent() {
         return false;
     }
+
+    @Override
+    public boolean hasOverlappingRendering() {
+        return false;
+    }
 }