Dark theme on/off - widget does not change

[shompoe]

When system dark theme is turned on or off the widget now stays the same until it has refreshed.

To reproduce, turn dark theme on or off. Note that all elements of the home screen have changed their colours, except the Todo widget. Tap the refresh icon on the Todo widget, now it has changed its colours

[yvolk]

The widget tries to subscribe to several environment change events, see

todoagenda/app/src/main/kotlin/org/andstatus/todoagenda/EnvironmentChangedReceiver.kt

Lines 171 to 174 in d40373a

	filter.addAction(Intent.ACTION_CONFIGURATION_CHANGED)
	filter.addAction(Intent.ACTION_DREAMING_STOPPED)
	filter.addAction(Intent.ACTION_TIME_CHANGED)
	filter.addAction(Intent.ACTION_TIMEZONE_CHANGED)

Maybe we need to subscribe to another one in order to know, when a Theme is changed...

I see something related in these questions:

• https://stackoverflow.com/questions/59694023/listening-on-dark-theme-in-notification-area-toggle-and-be-notified-of-a-chang - will look if this works for a BroadcastReceiver