By clearing `sessionStorage` and unsubscribing from `Location` events,
after each test, we reduce the possibility of potential
[spooky action at a distance][1]-type of failures in the future.
This does not have an impact on the actual app, since `ScrollService` is
currently expected to live throughout the lifetime of the app. Still,
unsubscribing from `Location` events keeps the code consistent with how
other `ScrollService` listeners are handled (e.g. for `window` events).
[1]: https://en.wikipedia.org/wiki/Action_at_a_distance_(computer_programming)
PR Close#33937
9e45203679