Plugins: avoid app importDashboards() NPE (#18128)

* tables display

* add missing file

* adding toolbar option

* adding toolbar option

* add items to index

* use root import path

* merge master

* show tables info

* add importDashboards code

* remove table changes

* remove table changes

* use deprecation warning

(cherry picked from commit 06b43f6d4b)

docs/sources/plugins/developing/apps.md

@@ -37,15 +37,11 @@ export class ConfigCtrl {
 
   postUpdate() {
     if (!this.appModel.enabled) {
-      return this.$q.resolve();
+      return;
     }
-    return this.appEditCtrl.importDashboards().then(() => {
-      this.enabled = true;
-      return {
-        url: "plugins/raintank-kubernetes-app/page/clusters",
-        message: "Kubernetes App enabled!"
-      };
-    });
+
+    // TODO, whatever you want
+    console.log('Post Update:', this);
   }
 }
 ConfigCtrl.templateUrl = 'components/config/config.html';