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
import java.util.function.Predicate;
import java.util.function.Supplier;
import java.util.function.UnaryOperator;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import static java.util.Collections.emptyList;
import static java.util.Collections.emptyMap;
import static java.util.Collections.singletonList;
import static org.elasticsearch.xpack.core.XPackSettings.API_KEY_SERVICE_ENABLED_SETTING;
import static org.elasticsearch.xpack.core.XPackSettings.HTTP_SSL_ENABLED;
import static org.elasticsearch.xpack.core.security.SecurityField.FIELD_LEVEL_SECURITY_FEATURE;
import static org.elasticsearch.xpack.security.operator.OperatorPrivileges.OPERATOR_PRIVILEGES_ENABLED;
public class Security extends Plugin
    implements
        SystemIndexPlugin,
        IngestPlugin,
        NetworkPlugin,
        ClusterPlugin,
        DiscoveryPlugin,
        MapperPlugin,
        ExtensiblePlugin,
        SearchPlugin,
        RestInterceptorActionPlugin {
    public static final String SECURITY_CRYPTO_THREAD_POOL_NAME = XPackField.SECURITY + "-crypto";
    
    public static final LicensedFeature.Momentary IP_FILTERING_FEATURE = LicensedFeature.momentaryLenient(
        null,
        "security-ip-filtering",
        License.OperationMode.GOLD
    );