These toggles only apply to the portal system, so only restrict access
for sandboxed apps. Non-sandboxed apps (installed into `/usr/bin`) can
always access these resources on typical distributions.

In future, perhaps integration with a MAC (like SELinux) could restrict
access to the camera/microphone/GPS for non-sandboxed applications —
but we invented sandboxing to avoid having to do that, so it seems
unlikely that’s ever going to be implemented. If it is, this wording
can change again.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Fixes: #741