Remember previous state

[JohnVeness]

I almost exclusively use the Remote tab in RoMote, but if the app is killed (either manually or automatically by Android due to inactivity), RoMote defaults to the Devices tab next time it is run. Even though it's only one swipe, it would be nice as a quality-of-life issue to have the app remember and navigate to the previous tab that was open.

More generally, although less importantly to me specifically, maybe the app should remember the entire previous state, e.g. the scroll position in the Channels tab, whether the keyboard is open in the Remote tab, etc.

Many thanks for this app :)

EDIT: I've just realised my main request is very similar to #23, although maybe the more general "remember state" is sufficiently different to keep this one open.