[Maps] do not show joins UI for ES geo grid source (#30309)

x-pack/plugins/maps/public/shared/layers/layer.js

@@ -51,7 +51,7 @@ export class AbstractLayer {
   }
 
   isJoinable() {
-    return false;
+    return this._source.isJoinable();
   }
 
   async getDisplayName() {

x-pack/plugins/maps/public/shared/layers/sources/es_geo_grid_source/es_geo_grid_source.js

@@ -113,6 +113,10 @@ export class ESGeoGridSource extends AbstractESSource {
     return true;
   }
 
+  isJoinable() {
+    return false;
+  }
+
   getGridResolution() {
     return this._descriptor.resolution;
   }

x-pack/plugins/maps/public/shared/layers/sources/source.js

@@ -89,6 +89,10 @@ export class AbstractSource {
   getGeoGridPrecision() {
     return 0;
   }
+
+  isJoinable() {
+    return false;
+  }
 }
 
 

x-pack/plugins/maps/public/shared/layers/sources/vector_source.js

@@ -102,4 +102,7 @@ export class AbstractVectorSource extends AbstractSource {
     return false;
   }
 
+  isJoinable() {
+    return true;
+  }
 }

x-pack/plugins/maps/public/shared/layers/vector_layer.js

@@ -67,10 +67,6 @@ export class VectorLayer extends AbstractLayer {
     });
   }
 
-  isJoinable() {
-    return true;
-  }
-
   getJoins() {
     return this._joins.slice();
   }