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 #18201. Relates to #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';