When resolving a user's roles, if there are any roles that depend on DLS/FLS, and that is not permitted by the current license, we skip them.
https://github.com/elastic/elasticsearch/blob/f435488484ec844962d49371b8917c135fe6f714/x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authz/store/CompositeRolesStore.java#L188-L192

However, we do not perform any logging in this circumstance, and rely on the user discovering that their roles are missing.

We should
1. Add a `WARN` log message
2. Add a Warning header

when this occurs. 
x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authz/store/CompositeRolesStoreTests.java
reservedRolesStore,
            customRoleProviders,
            null,
            xPackLicenseState,
            null,
            null,
            null,
            rds -> effectiveRoleDescriptors.set(rds),
            null
        );
        Set<String> roleNames = Sets.newHashSet("roleA");
        PlainActionFuture<Role> future = new PlainActionFuture<>();
        getRoleForRoleNames(compositeRolesStore, roleNames, future);
        Role role = future.actionGet();
        assertThat(effectiveRoleDescriptors.get(), hasSize(0));
        effectiveRoleDescriptors.set(null);
        verify(xPackLicenseState).disableUsageTracking(Security.CUSTOM_ROLE_PROVIDERS_FEATURE, "custom");
        
        assertEquals(0, role.indices().groups().length);
        when(xPackLicenseState.isAllowed(Security.CUSTOM_ROLE_PROVIDERS_FEATURE)).thenReturn(true);
        licenseListener.get().licenseStateChanged();
        roleNames = Sets.newHashSet("roleA");
        future = new PlainActionFuture<>();
        getRoleForRoleNames(compositeRolesStore, roleNames, future);
        role = future.actionGet();
        assertThat(effectiveRoleDescriptors.get(), containsInAnyOrder(roleA));
        effectiveRoleDescriptors.set(null);
        verify(xPackLicenseState).enableUsageTracking(Security.CUSTOM_ROLE_PROVIDERS_FEATURE, "custom");
        
        assertEquals(1, role.indices().groups().length);