As we are rolling out the user profile feature, we'd like to expand the [Usage API](https://www.elastic.co/guide/en/elasticsearch/reference/current/usage-api.html) to report usage stats of user profiles such as (1) number of enabled user profiles and (2) number of user profiles that are [activated](https://www.elastic.co/guide/en/elasticsearch/reference/current/security-api-activate-user-profile.html) over the past X days. 

Response of the Usage API already contains a `security` field that groups relevant stats from security related features. We expect the new stats for user profiles should be added under it as well, for example:
```
{
  "security: {
    "user_profile": {
      "activated": 78,
      "recently_activated": 42  <1>
    }
  }
}
```
<1> The use of `recently_` is chosen to avoid the field to be tied to a specific time period so it is easier to evolve the definition in future.

x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/Security.java
getNettySharedGroupFactory(settings),
                tracer
            )
        );
        return httpTransports;
    }
    @Override
    public UnaryOperator<RestHandler> getRestHandlerInterceptor(ThreadContext threadContext) {
        final boolean extractClientCertificate;
        if (enabled && HTTP_SSL_ENABLED.get(settings)) {
            final SslConfiguration httpSSLConfig = getSslService().getHttpTransportSSLConfiguration();
            extractClientCertificate = SSLService.isSSLClientAuthEnabled(httpSSLConfig);
        } else {
            extractClientCertificate = false;
        }
        return handler -> new SecurityRestFilter(
            settings,
            threadContext,
            authcService.get(),
            secondayAuthc.get(),
            handler,
            extractClientCertificate
        );
    }
    @Override
    public List<ExecutorBuilder<?>> getExecutorBuilders(final Settings settings) {
        if (enabled) {
            final int allocatedProcessors = EsExecutors.allocatedProcessors(settings);
            return List.of(
                new FixedExecutorBuilder(settings, TokenService.THREAD_POOL_NAME, 1, 1000, "xpack.security.authc.token.thread_pool", false),