fix(cdk/a11y): add ConfigurableFocusTrapConfig to the public API

- `ConfigurableFocusTrap` is already in the public API and it depends on this class
- fix alphabetization of exports

Relates to angular#18201. Relates to angular#22136.

Author: Splaktar

src/cdk/a11y/public-api.ts

@@ -10,9 +10,10 @@ export * from './key-manager/activedescendant-key-manager';
 export * from './key-manager/focus-key-manager';
 export * from './key-manager/list-key-manager';
 export * from './focus-trap/configurable-focus-trap';
+export * from './focus-trap/configurable-focus-trap-config';
+export * from './focus-trap/configurable-focus-trap-factory';
 export * from './focus-trap/event-listener-inert-strategy';
 export * from './focus-trap/focus-trap';
-export * from './focus-trap/configurable-focus-trap-factory';
 export * from './focus-trap/focus-trap-inert-strategy';
 export * from './interactivity-checker/interactivity-checker';
 export * from './live-announcer/live-announcer';

tools/public_api_guard/cdk/a11y.d.ts

@@ -70,6 +70,10 @@ export declare class ConfigurableFocusTrap extends FocusTrap implements ManagedF
     destroy(): void;
 }
 
+export declare class ConfigurableFocusTrapConfig {
+    defer: boolean;
+}
+
 export declare class ConfigurableFocusTrapFactory {
     constructor(_checker: InteractivityChecker, _ngZone: NgZone, _focusTrapManager: FocusTrapManager, _document: any, _inertStrategy?: FocusTrapInertStrategy);
     create(element: HTMLElement, config?: ConfigurableFocusTrapConfig): ConfigurableFocusTrap;