fix(accordion): initialize destroyOnHide from configuration

src/accordion/accordion-config.spec.ts

@@ -7,6 +7,7 @@ describe('ngb-accordion-config', () => {
 		const config = new NgbAccordionConfig(new NgbConfig());
 
 		expect(config.closeOthers).toBe(false);
+		expect(config.destroyOnHide).toBe(true);
 		expect(config.type).toBeUndefined();
 	});
 });

src/accordion/accordion-config.ts

@@ -10,6 +10,8 @@ import { NgbConfig } from '../ngb-config';
 @Injectable({ providedIn: 'root' })
 export class NgbAccordionConfig {
 	closeOthers = false;
+	destroyOnHide = true;
+
 	/**
 	 * @deprecated 14.1.0
 	 */

src/accordion/accordion.directive.ts

@@ -384,7 +384,7 @@ export class NgbAccordionDirective {
 	 *
 	 * This property can be overwritten at the [`NgbAccordionItem`](#/components/accordion/api#NgbAccordionItem) level
 	 */
-	@Input() destroyOnHide = true;
+	@Input() destroyOnHide: boolean;
 
 	/**
 	 * Event emitted before expanding animation starts. The payload is the id of shown accordion item.
@@ -416,6 +416,7 @@ export class NgbAccordionDirective {
 	constructor(config: NgbAccordionConfig) {
 		this.animation = config.animation;
 		this.closeOthers = config.closeOthers;
+		this.destroyOnHide = config.destroyOnHide;
 	}
 
 	/**