Back button on activity returns to OAuth provider after login

[carlobeltrame]

When visiting or refreshing an activity detail page while not logged in (e.g. after the session expired), one is prompted to log in. If one then uses an OAuth login, one correctly gets to the activity detail page. However, using the UI back button on the top right of the activity detail card will return the user to the OAuth provider.

Maybe we should check in the back button whether the user would navigate to an URL outside of eCamp, and instead navigate to the dashboard or picasso in that case?