Remove/hide Aeroplane/Airplane mode until it works correctly
This is related to, but separate from, existing issues about fixing aeroplane mode: gnome-control-center#121 (closed), https://bugzilla.gnome.org/show_bug.cgi?id=761051 (further functional problems listed in the latter).
The current airplane mode implementation is broken in several ways, e.g.:
- the state of radios is not remembered/restored when the aeroplane mode is switched off; instead an arbitrary set of radios are switched on even if they were off before (e.g. Bluetooth, but not WLAN);
- it toggles itself on automatically when (GSD thinks) all radios are off;
- GSD incorrectly detects that all radios are off when they are not (e.g. cellular modem is still on, but when WLAN is disabled, aeroplane mode gets enabled;
- it doesn't actually disable all radios when it self-enables (e.g. in the above case, the cellular modem remains active, and if mobile data was enabled, a cellular data connection is still available).
In summary, it's a frustrating mess currently, unfortunately.
Given this, the feature should be disabled/hidden until either:
- it does not cause problems just by being present as a feature (i.e. it should operate explicitly only, and independent of radio states - e.g. switching off all radios should not enable aeroplane mode); or
- it works in a predictable manner consistent with user expectations:
- radio states are detected correctly;
- all radios are restored to their previous state when aeroplane mode is switched off.