Made debug mode actually work on release builds.

The settings is still hidden unless settings screen is tapped 6 times.
Also ensured that any old installs won’t be stuck with debug mode activated.
Note that once activated the debug mode setting only persists until the app quits - the setting is not remembered. (Technically it is, but it’s overridden each time app starts to be “NO” to ensure old installs aren’t stuck in debug mode).