Cache dashboard and change list view page
Cache dashboard and change list view page

We want to maintain the selected change index if the user goes to the
change page and comes back to the dashboard in the component itself.

Currently the view is re-created without the cache and we need to rely
on the viewState which can be removed after this change.

When going to the change page and coming back the paramsChanged method
is called in GrChangeListView which ends up fetching a new set of
changes. [1]

[1] https://cs.opensource.google/gerrit/gerrit/gerrit/+/master:polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts;l=312?q=%22this.changesPerPage%20%3D%20prefs.changes_per_page%22

Release-Notes: skip
Change-Id: I3320bd27cd1f1e5de4469a34139aff9a02a56d13

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