[fenix] For https://github.com/mozilla-mobile/fenix/issues/11660: added prefetch for topsites and update in onCreateView() (https://github.com/mozilla-mobile/fenix/pull/11668)
* For https://github.com/mozilla-mobile/fenix/issues/11660:added prefetch for topsites
TopSites will be prefetched with observerOnce (wrapper around observerForever).
Also, the SessionControlView.update() is called right away instead of waiting from consumeFrom
in the HomeFragment.onCreateView() which will allow the UI to render all at once on its first
perform traversal
* Removed the submitList(null) since it retriggered a drawing on lower end device