ESPV2 1.49.0 Envoy bug removed guard prohibit_route_refresh_after_response_headers_sent

Since updated to ESPV2 version `1.49.0`, we noticed the errors below in the log. I took a look at Envoy issues but couldnt find any issue related to this. Just wondering if it is an issue with Envoy or a misconfiguration somewhere?

```
[22][envoy_bug]#14 UNKNOWN [0x7d8b9bb74510]
[22][envoy_bug]#13 main [0x55ab26e33daa]
[22][envoy_bug]#12 Envoy::MainCommon::main() [0x55ab26e36cb0]
[22][envoy_bug]#11 Envoy::MainCommon::MainCommon() [0x55ab26e36b5b]
[22][envoy_bug]#10 Envoy::MainCommonBase::MainCommonBase() [0x55ab26e36295]
[22][envoy_bug]#9 Envoy::StrippedMainBase::StrippedMainBase() [0x55ab26e572cb]
[22][envoy_bug]#8 std::_Function_handler<>::_M_invoke() [0x55ab26e3a330]
[22][envoy_bug]#7 Envoy::Server::InstanceBase::initialize() [0x55ab26fc06e4]
[22][envoy_bug]#6 Envoy::Server::InstanceBase::initializeOrThrow() [0x55ab26fc468c]
[22][envoy_bug]#5 Envoy::ProdComponentFactory::createRuntime() [0x55ab26e56ab4]
[22][envoy_bug]#4 Envoy::Server::InstanceUtil::createRuntime() [0x55ab26fc9696]
[22][envoy_bug]#3 Envoy::Runtime::LoaderImpl::LoaderImpl() [0x55ab27ab6ae1]
[22][envoy_bug]#2 Envoy::Runtime::LoaderImpl::loadNewSnapshot() [0x55ab27ab7a2d]
[22][envoy_bug]#1 Envoy::Runtime::LoaderImpl::createNewSnapshot() [0x55ab27ab9afd]
[22][envoy_bug]#0 Envoy::Runtime::ProtoLayer::ProtoLayer() [0x55ab27ab5cbd]
[22][envoy_bug]stacktrace for envoy bug
[22][envoy_bug]envoy bug failure: false. Details: Using a removed guard envoy.reloadable_features.prohibit_route_refresh_after_response_headers_sent. In future version of Envoy this will be treated as invalid configuration
```

Start with the ESPV2 1.49.0 upgrade and the logged Envoy runtime error about envoy.reloadable_features.prohibit_route_refresh_after_response_headers_sent. Trace where that runtime configuration is supplied and compare it with the Envoy version in use. Done means determining whether ESPV2 configuration or Envoy behavior is responsible and documenting or addressing the confirmed cause.

Written by the indexing model from the issue text.