Add a toggle for edge-to-edge mode.
Normally we would want to enable edge-to-edge by default (in fact, we
still do). However, some phones (once again, samsung) don't provide
Auxio with actual window insets. As a result, we need to add a toggle
so that it can be disabled on busted devices.
Did you know that even when Auxio has it's edge-to-edge functionality
busted, Samsung Music works just fine? Very interesting.
Resolves#149.
c929357d76