Are the lb_policy and lb_config forced to match?

*Description*:
Currently in clusterInfoImpl when the lb_configs are loaded, it doesn't check if the lb_policy matches the config that's loaded. We have a separate member for the lb_policy and other members for each config type. Is there anything to stop the user from setting a round_robin config but also setting the lb_policy to least request? If there isn't, should anything be done about that?

*Relevant Links*:
[Current implementation of how the lb config members are initialized](https://github.com/envoyproxy/envoy/blob/0737bac16fa47ebe6a9c68d16a6c3244eb7ec051/source/common/upstream/upstream_impl.cc#L1011)

[Current location of where lb_policy is set](https://github.com/envoyproxy/envoy/blob/0737bac16fa47ebe6a9c68d16a6c3244eb7ec051/source/common/upstream/upstream_impl.cc#L1081)