Fix issue where button does not get centered when partially of screen initially.
Fix issue where button does not get centered when partially of screen initially.

eximpression/HTHorizontalSelectionList,various/HTHorizontalSelectionList,rahul-apple/HTHorizontalSelectionList,zilaiyedaren/HTHorizontalSelectionList,rahul-apple/HTHorizontalSelectionList,rahul-apple/HTHorizontalSelectionList,prehypenyc/HTHorizontalSelectionList,prehypenyc/HTHorizontalSelectionList,zilaiyedaren/HTHorizontalSelectionList,eximpression/HTHorizontalSelectionList,prehypenyc/HTHorizontalSelectionList,hightower/HTHorizontalSelectionList,prehypenyc/HTHorizontalSelectionList,various/HTHorizontalSelectionList,hightower/HTHorizontalSelectionList,eximpression/HTHorizontalSelectionList,zilaiyedaren/HTHorizontalSelectionList,eximpression/HTHorizontalSelectionList,zilaiyedaren/HTHorizontalSelectionList,rahul-apple/HTHorizontalSelectionList,various/HTHorizontalSelectionList,various/HTHorizontalSelectionList