RCFilters: Fix live update

When Id55702ecbe6b96ee57453d4f86f20bd94a401d7c
introduced the MainWrapperWidget, it changed
the order on initialization, which prevents
ChangesListViewModel from getting the initial
value of the 'from' parameter and thus
disables polling for new changes.

This patch ensures ChangesListViewModel is
given the initial form in its constructor
so it can extract what it needs from it
before the page DOM is being transformed.

Bug: T182788
Change-Id: I1b72790194877ff0f200c87e4f40a942f1ccac3b