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/profile/ProfileService.java
new SuggestProfilesResponse(profileHits, searchResponse.getTook().millis(), searchHits.getTotalHits())
                        );
                    }, listener::onFailure)
                )
            );
        });
    }
    public void setEnabled(String uid, boolean enabled, RefreshPolicy refreshPolicy, ActionListener<AcknowledgedResponse> listener) {
        final XContentBuilder builder;
        try {
            builder = XContentFactory.jsonBuilder();
            builder.startObject().field("user_profile", Map.of("enabled", enabled)).endObject();
        } catch (IOException e) {
            listener.onFailure(e);
            return;
        }
        doUpdate(buildUpdateRequest(uid, builder, refreshPolicy), listener.map(updateResponse -> AcknowledgedResponse.TRUE));
    }
    public void searchProfilesForSubjects(List<Subject> subjects, ActionListener<SubjectSearchResultsAndErrors<Profile>> listener) {
        searchVersionedDocumentsForSubjects(subjects, ActionListener.wrap(resultsAndErrors -> {
            if (resultsAndErrors == null) {
                
                listener.onResponse(null);
                return;
            }
            listener.onResponse(new SubjectSearchResultsAndErrors<>(resultsAndErrors.results().stream().map(t -> {
                if (t.v2() != null) {
                    return new Tuple<>(t.v1(), t.v2().toProfile(Set.of()));
                } else {
                    return new Tuple<>(t.v1(), (Profile) null);