detail button semantic description and screen reader announce into button subscribe

src/Mobile/Pages/ShowDetailPage.xaml

@@ -39,6 +39,7 @@
                                      HeightRequest="38"
                                      Source="player_play.png"
                                      VerticalOptions="Center"
+                                     SemanticProperties.Description="{x:Static res:AppResource.Semantic_Description_Tap_Play_Episode}"
                                      Command="{Binding Source={RelativeSource AncestorType={x:Type viewmodels:ShowDetailViewModel}}, Path=PlayEpisodeCommand}"
                                      CommandParameter="{Binding}"
                                      WidthRequest="38">
@@ -65,6 +66,7 @@
                                      VerticalOptions="Center"
                                      Source="clockpink.png"
                                      HeightRequest="28"
+                                     SemanticProperties.Description="{x:Static res:AppResource.Semantic_Description_Tap_Listen_Later}"
                                      Command="{Binding Source={RelativeSource AncestorType={x:Type viewmodels:ShowDetailViewModel}}, Path=AddToListenLaterCommand}"
                                      CommandParameter="{Binding}"
                                      WidthRequest="28">

src/Mobile/Resources/Strings/AppResource.Designer.cs

@@ -221,7 +221,16 @@ namespace Microsoft.NetConf2021.Maui.Resources.Strings {
                 return ResourceManager.GetString("See_All_Categories", resourceCulture);
             }
         }
-        
+
+        /// <summary>
+        ///   Looks up a localized string similar to Tap to listen later.
+        /// </summary>
+        internal static string Semantic_Description_Tap_Listen_Later {
+            get {
+                return ResourceManager.GetString("Semantic_Description_Tap_Listen_Later", resourceCulture);
+            }
+        }
+
         /// <summary>
         ///   Looks up a localized string similar to Tap to play or pause an episode.
         /// </summary>

src/Mobile/Resources/Strings/AppResource.resx

@@ -171,6 +171,9 @@
   <data name="See_All_Categories" xml:space="preserve">
     <value>See All Categories</value>
   </data>
+  <data name="Semantic_Description_Tap_Listen_Later" xml:space="preserve">
+    <value>Tap to listen later</value>
+  </data>
   <data name="Semantic_Description_Tap_Play_Episode" xml:space="preserve">
     <value>Tap to play or pause an episode</value>
   </data>

src/Mobile/Services/SubscriptionsService.cs

@@ -21,9 +21,15 @@ public class SubscriptionsService
 
         if (IsSubscribed(show.Id))
         {
+            SemanticScreenReader.Announce(string.Format("Unsubscribe to show {0}", show.Title));
             await UnSubscribeFromShowAsync(show);
             return;
         }
+        else
+        {
+            SemanticScreenReader.Announce(string.Format("Subscribe to show {0}", show.Title));
+        }
+
 
         this.subscribedShows.Add(show);
     }