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
@SuppressWarnings("unchecked")
            ActionListener<RoleRetrievalResult> callback = (ActionListener<RoleRetrievalResult>) invocationOnMock.getArguments()[1];
            callback.onResponse(RoleRetrievalResult.failure(new RuntimeException("intentionally failed!")));
            return null;
        }).when(nativeRolesStore).getRoleDescriptors(isASet(), anyActionListener());
        final ReservedRolesStore reservedRolesStore = spy(new ReservedRolesStore());
        ThreadContext threadContext = new ThreadContext(SECURITY_ENABLED_SETTINGS);
        ApiKeyService apiKeyService = spy(
            new ApiKeyService(
                SECURITY_ENABLED_SETTINGS,
                Clock.systemUTC(),
                mock(Client.class),
                mock(SecurityIndexManager.class),
                mock(ClusterService.class),
                mock(CacheInvalidatorRegistry.class),
                mock(ThreadPool.class)
            )
        );
        NativePrivilegeStore nativePrivStore = mock(NativePrivilegeStore.class);
        doAnswer(invocationOnMock -> {
            @SuppressWarnings("unchecked")
            ActionListener<Collection<ApplicationPrivilegeDescriptor>> listener = (ActionListener<
                Collection<ApplicationPrivilegeDescriptor>>) invocationOnMock.getArguments()[2];
            listener.onResponse(Collections.emptyList());
            return Void.TYPE;
        }).when(nativePrivStore).getPrivileges(anyCollection(), anyCollection(), anyActionListener());
        final AtomicReference<Collection<RoleDescriptor>> effectiveRoleDescriptors = new AtomicReference<Collection<RoleDescriptor>>();
        final CompositeRolesStore compositeRolesStore = buildCompositeRolesStore(
            SECURITY_ENABLED_SETTINGS,
            fileRolesStore,