Fix widget toggle not disabling On Demand before stopping VPN

Store wasOnDemandEnabled flag in providerConfiguration so the widget
can restore On Demand state on next start. Clear the flag when On
Demand is explicitly disabled in settings or when starting from the
main app.

ApplicationLibrary/Views/Log/LogViewModel.swift

@@ -179,7 +179,7 @@ public class LogViewModel: BaseViewModel {
     public init(commandClient: CommandClient, searchText: String = "") {
         self.commandClient = commandClient
         self.searchText = searchText
-        self.isSearching = !searchText.isEmpty
+        isSearching = !searchText.isEmpty
         super.init()
         dataModel = LogDataModel(commandClient: commandClient, viewModel: self)
     }