kiosk: Skip network check for offline enabled app.

chrome/test/data/chromeos/app_mode/offline_enabled_app_profile/Preferences

+{
+   "extensions": {
+      "settings": {
+         "ajoggoflpgplnnjkjamcmbepjdjdnpdp": {
+            "active_permissions": {
+               "api": [ "power" ],
+               "manifest_permissions": [  ]
+            },
+            "app_launcher_ordinal": "w",
+            "content_settings": [  ],
+            "creation_flags": 1,
+            "events": [ "app.runtime.onLaunched" ],
+            "from_bookmark": false,
+            "from_webstore": false,
+            "granted_permissions": {
+               "api": [ "power" ],
+               "manifest_permissions": [  ]
+            },
+            "incognito_content_settings": [  ],
+            "incognito_preferences": {
+
+            },
+            "initial_keybindings_set": true,
+            "install_time": "13036543351940246",
+            "location": 1,
+            "manifest": {
+               "app": {
+                  "background": {
+                     "scripts": [ "main.js" ]
+                  }
+               },
+               "icons": {
+                  "128": "icon-128.png",
+                  "16": "icon-16.png"
+               },
+               "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwVSEHMxDHSOLV9HT3KW7uHL9CvKNmXLdLqicNDc8gdNYo1yQ0aNc1NVSO6JloMIJEX0S8lwDxgZmLsxQ6wQaaU4XeLVqjKK8iOcSzH3mYIffoM94FfdyLg6AWQkpEYGNi7q86uBhpeeZO5+1oQC+oQPEdmv90Oper1KmrysJoTMhRi3cbSP2nlnHn2c3ud3CXaxfQQh5cXLnXmGYrS2eYssEJoLe9WdCd7FvEVOC+0akweEeUPiHtOn3hZUdq6jmNEfGHtMz7xeFAQjfhI1smy7ZIr9hcucVD6UNKcxt5VQgzGwaIp0HmLa6mbkGrXRb2yZ/U6wfrlt/skqAtQ2Y1wIDAQAB",
+               "kiosk_enabled": true,
+               "manifest_version": 2,
+               "minimum_chrome_version": "24.0.1307.0",
+               "name": "Test Kiosk App",
+               "offline_enabled": true,
+               "permissions": [ "power" ],
+               "version": "1.0.0"
+            },
+            "page_ordinal": "n",
+            "path": "ajoggoflpgplnnjkjamcmbepjdjdnpdp/1.0.0_0",
+            "preferences": {
+
+            },
+            "regular_only_preferences": {
+
+            },
+            "running": true,
+            "state": 1,
+            "was_installed_by_default": false
+         }
+      }
+   }
+}