Take headers into account when expanding a ExpListView group.

The possible scroll that happen after expanding a group did not take the possible
existing headers into account.

Change-Id: I5dc381baa7c54580e992e26a1ed55102afcb16b0
diff --git a/core/java/android/widget/ExpandableListView.java b/core/java/android/widget/ExpandableListView.java
index 79abd4b..9cc8bd5 100644
--- a/core/java/android/widget/ExpandableListView.java
+++ b/core/java/android/widget/ExpandableListView.java
@@ -547,9 +547,10 @@
                 
                 final int groupPos = posMetadata.position.groupPos;
                 final int groupFlatPos = posMetadata.position.flatListPos;
-                
-                smoothScrollToPosition(groupFlatPos + mAdapter.getChildrenCount(groupPos),
-                        groupFlatPos);
+
+                final int shiftedGroupPosition = groupFlatPos + getHeaderViewsCount(); 
+                smoothScrollToPosition(shiftedGroupPosition + mAdapter.getChildrenCount(groupPos),
+                        shiftedGroupPosition);
             }
 
             returnValue = true;