Resolves #283 Add possibility to restrat HA

lib/entity_widgets/common/flat_service_button.dart

@@ -4,29 +4,30 @@ class FlatServiceButton extends StatelessWidget {
 
   final String serviceDomain;
   final String serviceName;
+  final String entityId;
   final String text;
   final double fontSize;
 
   FlatServiceButton({
     Key key,
-    this.serviceDomain,
-    this.serviceName: "turn_on",
+    @required this.serviceDomain,
+    @required this.serviceName,
+    @required this.entityId,
     @required this.text,
     this.fontSize: Sizes.stateFontSize
   }) : super(key: key);
 
-  void _setNewState(Entity entity) {
-    eventBus.fire(new ServiceCallEvent(serviceDomain ?? entity.domain, serviceName, entity.entityId, null));
+  void _setNewState() {
+    eventBus.fire(new ServiceCallEvent(serviceDomain, serviceName, entityId, null));
   }
 
   @override
   Widget build(BuildContext context) {
-    final entityModel = EntityModel.of(context);
     return SizedBox(
         height: fontSize*2.5,
         child: FlatButton(
           onPressed: (() {
-            _setNewState(entityModel.entityWrapper.entity);
+            _setNewState();
           }),
           child: Text(
             text,