Calculating end scroll offset was using the distance between the last child and the last focal keyline. When the last child came before the last keyline, an unexpected scroll offset was returned. This also adds a dropdown to the catalog demo to allow setting the number of items in the carousel.
PiperOrigin-RevId: 508739119
This removes CenteredCarouselConfigration and its superclass MultibrowseCarouselConfiguration and renames StartCarouselConfiguration to MultiBrowseCarouselConfiguration.
PiperOrigin-RevId: 506424085