Align zoom level settings (#11399)

- allow 0-level for WMS services
- use zoom level 2, centered at 0,0 as new default when tilemap viz opens

src/core_plugins/kbn_vislib_vis_types/public/tile_map.js

@@ -29,7 +29,7 @@ export default function TileMapVisType(Private, getAppState, courier, config) {
         heatBlur: 15,
         heatNormalizeData: true,
         legendPosition: 'bottomright',
-        mapZoom: 0,
+        mapZoom: 2,
         mapCenter: [0, 0],
         wms: config.get('visualization:tileMap:WMSdefaults')
       },

src/ui/public/vis_maps/lib/tilemap_settings.js

@@ -159,11 +159,9 @@ uiModules.get('kibana')
        * @return {{maxZoom: (*|number), minZoom: (*|number)}}
        */
       getMinMaxZoom(isWMSEnabled) {
-
-        //for backward compatibilty, we preserve the 1-18 setting. https://git.io/vMn5o
         if (isWMSEnabled) {
           return {
-            minZoom: 1,
+            minZoom: 0,
             maxZoom: 18
           };
         }

test/functional/apps/visualize/_tile_map.js

@@ -57,6 +57,11 @@ export default function ({ getService, getPageObjects }) {
 
         return PageObjects.visualize.collapseChart()
         .then(function () {
+          //level 1
+          return PageObjects.visualize.clickMapZoomOut();
+        })
+        .then(function () {
+          //level 0
           return PageObjects.visualize.clickMapZoomOut();
         })
         .then(function () {