- Preserve the flex items state across a configuration change in the demo app
- Throw an Exception when order or alignContent which aren't supported by
  FlexboxLayoutManager are changed (setXXXX is invoked)
- Clear the existing flex lines and views if an incompatible, in which prior views
  states or flex lines states can't be shared, attribute change happens
  (e.g. flex direction is changd from row to column)