translations: fix missing string derp

This is actually really serious, it would crash without.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
activity: fix onBackPressed() handling

The previous solution was always a little bit buggy, so
here is a new one. This also has the nice side-effect
that the action bar title gets updated accordingly.

The back-counter logic is gone for now until i find a smart
way to implement it again.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
voltage: fix values wouldn't update

This line was missing in order to update the UI
with the new values.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
misc: add tcp congestion choice

Using the very generic new list preference implementation
and also including set on boot functionality in this, since
its such a little change.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>