If a route misses, AngularFireAnalytics errors

Can force this by pushing a bad route / prefix config or get multiple outlets confused, Analytics should not error, instead ignore.

Ran into this by having pathMatch: 'full' on the primary outlet's root url, navigating to a non-root path on another outlet, and doing a full refresh. IMO this is an Angular bug but we should not fail in this discovered case.

actualSnapshot is null.