Updated IdSvr for Xamarin-UWP signin related problems

docker-compose.override.yml

@@ -33,7 +33,7 @@ services:
       - ASPNETCORE_ENVIRONMENT=Development
       - ASPNETCORE_URLS=http://0.0.0.0:5105
       - SpaClient=http://${ESHOP_EXTERNAL_DNS_NAME_OR_IP}:5104
-      - XamarinCallback=http://${ESHOP_EXTERNAL_DNS_NAME_OR_IP}:5105
+      - XamarinCallback=http://${ESHOP_PROD_EXTERNAL_DNS_NAME_OR_IP}:5105/xamarincallback      #localhost do not work for UWP login, so we have to use "external" IP always
       - ConnectionStrings__DefaultConnection=Server=sql.data;Database=Microsoft.eShopOnContainers.Service.IdentityDb;User Id=sa;Password=Pass@word 
       - MvcClient=http://${ESHOP_EXTERNAL_DNS_NAME_OR_IP}:5100              #Local: You need to open your local dev-machine firewall at range 5100-5105.  
     ports:

docker-compose.prod.yml

@@ -38,7 +38,7 @@ services:
       - SpaClient=http://${ESHOP_PROD_EXTERNAL_DNS_NAME_OR_IP}:5104
       - ConnectionStrings__DefaultConnection=Server=sql.data;Database=Microsoft.eShopOnContainers.Service.IdentityDb;User Id=sa;Password=Pass@word 
       - MvcClient=http://${ESHOP_PROD_EXTERNAL_DNS_NAME_OR_IP}:5100              #Local: You need to open your host's firewall at range 5100-5105.  
-      - XamarinCallback=http://${ESHOP_PROD_EXTERNAL_DNS_NAME_OR_IP}:5105
+      - XamarinCallback=http://${ESHOP_PROD_EXTERNAL_DNS_NAME_OR_IP}:5105/xamarincallback
     ports:
       - "5105:5105"
 

src/Services/Identity/Identity.API/Configuration/Config.cs

@@ -59,7 +59,7 @@ namespace Identity.API.Configuration
                     ClientName = "eShop Xamarin OpenId Client",
                     AllowedGrantTypes = GrantTypes.Implicit,
                     AllowAccessTokensViaBrowser = true,
-                    RedirectUris =          { $"{clientsUrl["Xamarin"]}/" },
+                    RedirectUris =          { clientsUrl["Xamarin"] },
                     RequireConsent = false,
                     PostLogoutRedirectUris = { "http://13.88.8.119:5105/Account/Redirecting", "http://10.6.1.234:5105/Account/Redirecting" },
                     AllowedCorsOrigins =     { "http://eshopxamarin" },

src/Services/Identity/Identity.API/appsettings.json

@@ -4,7 +4,7 @@
   },
   "MvcClient": "http://localhost:5100",
   "SpaClient": "http://localhost:5104",
-  "XamarinCallback":  "http://localhost:5105",
+  "XamarinCallback":  "http://localhost:5105/xamarincallback",
   "Logging": {
     "IncludeScopes": false,
     "LogLevel": {