Use user preference for AM/PM or 24h

[ChildishGiant]

The user can chose if AM/PM or 24h is used but hourglass always uses a mix

24 hour:

AM/PM:

[ryonakano]

This is because Flatpak apps can't access to the host's gsettings. We uses the following method to detect the host's time format:

hourglass/src/Widgets/Alarm.vala

Lines 72 to 80 in 6d2570b

	private string get_time_string () {
	var system_time_format = new GLib.Settings ("org.gnome.desktop.interface");
	var time_format = Granite.DateTime.get_default_time_format (
	system_time_format.get_enum ("clock-format") == 1, false
	);
	return time.format (time_format);
	}

This works if the app installed to /usr/share/bin, but it won't work on the sandboxed environment. Hopefully if elementary/granite#528 is merged we can fix this issue but the PR is not reviewed/merged yet. 😢

[ChildishGiant]

Ah, I thought there may be some system-talk-name finish arg that could expose it but I imagine you've looked into that. Hopefully the linked PR gets merged then 😊