Add discovery support to Xbox integration (home-assistant#154912)

Author: tr4nt0r

homeassistant/components/xbox/manifest.json

@@ -4,7 +4,22 @@
   "codeowners": ["@hunterjm"],
   "config_flow": true,
   "dependencies": ["auth", "application_credentials"],
+  "dhcp": [
+    {
+      "hostname": "xbox*"
+    }
+  ],
   "documentation": "https://www.home-assistant.io/integrations/xbox",
   "iot_class": "cloud_polling",
-  "requirements": ["xbox-webapi==2.1.0"]
+  "requirements": ["xbox-webapi==2.1.0"],
+  "ssdp": [
+    {
+      "modelName": "Xbox 360",
+      "manufacturer": "Microsoft Corporation"
+    },
+    {
+      "modelName": "Xbox One",
+      "manufacturer": "Microsoft Corporation"
+    }
+  ]
 }

homeassistant/components/xbox/strings.json

@@ -9,6 +9,10 @@
         "data_description": {
           "implementation": "[%key:common::config_flow::description::implementation%]"
         }
+      },
+      "oauth_discovery": {
+        "description": "Home Assistant has found an Xbox device on your network. Press **Submit** to continue setting up the Xbox integration.",
+        "title": "Discovered Xbox device"
       }
     },
     "abort": {