message: style(layout): setting sticky property only for lg and above breakpoints
  ### Description
  The `position: sticky` property set at the 'md' and below was causing the columns to overlap each other.
diff: @mixin layout {
  .#{$prefix}--layout--sticky-mobile {
  - @include carbon--breakpoint-down('lg') {
  + @include carbon--breakpoint('lg') {
  position: sticky;
  top: 0;
  z-index: 1;
  