This section is represented by <realms><realm> element
<realm> <id>realm::RedHat_DB</id> <repository-id-ref>RedHat Repository DB</repository-id-ref> <identity-type-mappings> <identity-mapping>IDENTITY</identity-mapping> </identity-type-mappings> </realm>
<realm> element contains:
id - realm id
repository-id-ref - id of configured IdentityStoreRepository
identity-type-mappings
identity-mapping - name of IdentityObjectType that should be maped as Identity object on the API side