Use dark theme for Element Call (#5860)

* Use dark theme for element Call

* Make sure only the call screen is shown in dark mode.

Otherwise when you go into PiP the entire app has become dark.

---------

Co-authored-by: Doug <douglase@element.io>

ElementX/Sources/Screens/CallScreen/View/CallScreen.swift

@@ -26,6 +26,9 @@ struct CallScreen: View {
                 .toolbar { toolbar }
         }
         .alert(item: $context.alertInfo)
+        // Force dark mode for calls. Don't use .preferredColorScheme
+        // otherwise the whole app changes, visible when using the PiP.
+        .environment(\.colorScheme, .dark)
     }
     
     @ViewBuilder

ElementX/Sources/Services/ElementCall/ElementCallWidgetDriver.swift

@@ -102,7 +102,7 @@ final class ElementCallWidgetDriver: WidgetCapabilitiesProvider, ElementCallWidg
         }
         
         let languageTag = "\(Locale.current.language.languageCode ?? "en")-\(Locale.current.language.region ?? "US")"
-        let theme = colorScheme == .light ? "light" : "dark"
+        let theme = "dark"
         
         let urlString: String
         do {