Add id = 0 handling (#2201)

* Add id = 0 handling

* Add check in view creation

src/panels/lovelace/editor/config-elements/hui-view-editor.ts

@@ -28,7 +28,8 @@ export class HuiViewEditor extends hassLocalizeLitMixin(LitElement) {
     if (!this._config) {
       return "";
     }
-    return this._config.id || "";
+
+    return "id" in this._config ? this._config.id! : "";
   }
 
   get _title(): string {

src/panels/lovelace/editor/hui-dialog-edit-view.ts

@@ -42,7 +42,7 @@ export class HuiDialogEditView extends LitElement {
     if (
       !this._params.add &&
       this._params.viewConfig &&
-      !this._params.viewConfig.id
+      !("id" in this._params.viewConfig)
     ) {
       return html`
         <hui-migrate-config

src/panels/lovelace/hui-view.js

@@ -119,7 +119,7 @@ class HUIView extends localizeMixin(EventsMixin(PolymerElement)) {
 
   _addCard() {
     showEditCardDialog(this, {
-      viewId: this.config.id,
+      viewId: "id" in this.config ? String(this.config.id) : undefined,
       add: true,
       reloadLovelace: () => {
         this.fire("config-refresh");