[2.x] Fix issue where initial page data is coming from history state

[joetannenbaum]

When we initially decrypt the history state so that the router can restore any remembered data, we were setting it as the current history in the History class, causing the page to be loaded from that state rather than the initial page props on the page.

The page would then load the initial page props, but you'd get a flash of stale data.

This fixes that issue by storing the restore data as a separate one-time-use property.