The placeholders only existed on the home rows; the shared list screens
(My videos, Search, Subscriptions, History, channel pages) still used a
full-screen spinner, and the Channels screen did too. All of them now
show card-shaped placeholders: the in-grid initial pass keeps the page
header and a two-row placeholder block, growing lists swap the always-
visible bottom spinner chip for a placeholder row driven by the new
loadingMore state on PagedListViewModel, and the channels screen shows
stub header bars plus placeholder rows while it starts up.
Closes#19
Jeena
52a0ba8fb9