Backup onboarding: Show close button when welcome is skipped (#23567)

src/panels/config/backup/dialogs/dialog-backup-onboarding.ts

@@ -90,7 +90,7 @@ class DialogBackupOnboarding extends LitElement implements HassDialog {
 
   public showDialog(params: BackupOnboardingDialogParams): void {
     this._params = params;
-    this._step = params.skipWelcome ? STEPS[1] : STEPS[0];
+    this._step = this._firstStep;
     this._config = RECOMMENDED_CONFIG;
 
     const agents: string[] = [];
@@ -129,6 +129,10 @@ class DialogBackupOnboarding extends LitElement implements HassDialog {
     this._params = undefined;
   }
 
+  private get _firstStep(): Step {
+    return this._params?.skipWelcome ? STEPS[1] : STEPS[0];
+  }
+
   private async _done() {
     if (!this._config) {
       return;
@@ -187,7 +191,7 @@ class DialogBackupOnboarding extends LitElement implements HassDialog {
     }
 
     const isLastStep = this._step === STEPS[STEPS.length - 1];
-    const isFirstStep = this._step === STEPS[0];
+    const isFirstStep = this._step === this._firstStep;
 
     return html`
       <ha-md-dialog disable-cancel-action open @closed=${this.closeDialog}>