Update manifest endpoint to new staging server (#9972)

points to staging version of v2 tile server

docs/setup/settings.asciidoc

@@ -23,8 +23,8 @@ to this Kibana instance.
 `kibana.index:`:: *Default: ".kibana"* Kibana uses an index in Elasticsearch to store saved searches, visualizations and
 dashboards. Kibana creates a new index if the index doesn’t already exist.
 `kibana.defaultAppId:`:: *Default: "discover"* The default application to load.
-[[tilemap-settings]]`tilemap.url:`:: *Default: `"https://tiles.elastic.co/v1/default/{z}/{x}/{y}.png?elastic_tile_service_tos=agree&my_app_name=kibana"`* The URL to the tile
-service that Kibana uses to display map tiles in tilemap visualizations.
+[[tilemap-settings]]`tilemap.url:`:: The URL to the tile
+service that Kibana uses to display map tiles in tilemap visualizations. By default, Kibana reads this url from an external metadata service, but users can still override this parameter to use their own Tile Map Service. For example: `"https://tiles.elastic.co/v2/default/{z}/{x}/{y}.png?elastic_tile_service_tos=agree&my_app_name=kibana"` 
 `tilemap.options.minZoom:`:: *Default: 1* The minimum zoom level.
 `tilemap.options.maxZoom:`:: *Default: 10* The maximum zoom level.
 `tilemap.options.attribution:`:: *Default: `"© [Elastic Tile Service](https://www.elastic.co/elastic-tile-service)"`* The map attribution string.

src/server/config/schema.js

@@ -132,7 +132,7 @@ module.exports = () => Joi.object({
     allowAnonymous: Joi.boolean().default(false)
   }).default(),
   tilemap: Joi.object({
-    manifestServiceUrl: Joi.string().default('https://proxy-tiles.elastic.co/v1/manifest'),
+    manifestServiceUrl: Joi.string().default('https://tiles-stage.elastic.co/v2/manifest'),
     url: Joi.string(),
     options: Joi.object({
       attribution: Joi.string(),