Fix audit log tests (#111706)

This ensures that the config object given to the `AuditService` setup
method is in fact the `xpack.security.audit.*` config options.
Previously the entire `xpack.security.*` config object would be passed
in.

The reason why this didn't fail the tests before was that both happen to
have a similarly named config option called `enabled`, which these tests
rely on.

x-pack/plugins/security/server/audit/audit_service.test.ts

@@ -29,7 +29,7 @@ import {
 jest.useFakeTimers();
 
 const createConfig = (settings: Partial<ConfigType['audit']>) => {
-  return ConfigSchema.validate(settings);
+  return ConfigSchema.validate({ audit: settings }).audit;
 };
 
 const logger = loggingSystemMock.createLogger();