Assert failure when accessing config_dump from admin interface

*Title*: *Assert failure when accessing config_dump from admin interface*

*Description*:
I have a binary of envoy built with a custom http filter. **The custom filter works without any issue**. However when I access admin interface on localhost:9000 after deploying an API, I get the following assert failure.

```[2021-02-10 14:13:12.485][7][critical][assert] [external/envoy/source/common/protobuf/utility.cc:730] assert failure: type_url_field_descriptor != nullptr && value_field_descriptor != nullptr && reflection->HasField(*message, type_url_field_descriptor). ```

It happens only when I use the ADS to config envoy. **When I statically configure envoy there's no assert failure**. The config of the custom http filter is defined from the following proto.

```
syntax = "proto3";

package envoy.extensions.filters.http.mgw_websocket.v3;

import "udpa/annotations/status.proto";
import "envoy/config/ratelimit/v3/rls.proto";
import "validate/validate.proto";

import "google/protobuf/duration.proto";

message RateLimit{
string domain = 1 [(validate.rules).string = {min_len: 1}];

string ratelimit_type = 2 [(validate.rules).string = {in:["downstream", "upstream", "", "default"]}];

google.protobuf.Duration timeout = 3;

bool failure_mode_deny = 4;

envoy.config.ratelimit.v3.RateLimitServiceConfig rate_limit_service = 5 [(validate.rules).message = {required: true}];
}
```
envoy.yaml is as follows.

```
admin:
access_log_path: /dev/null
address:
socket_address:
address: '${ROUTER_ADMIN_HOST}'
port_value: '${ROUTER_ADMIN_PORT}'
dynamic_resources:
ads_config:
api_type: GRPC
transport_api_version: V3
grpc_services:
- envoy_grpc:
cluster_name: xds_cluster
cds_config:
ads: {}
resource_api_version: V3
lds_config:
ads: {}
resource_api_version: V3
node:
cluster: '${ROUTER_CLUSTER}'
id: '${ROUTER_LABEL}'
static_resources:
clusters:
- name: xds_cluster
type: STRICT_DNS
connect_timeout: 1s
hosts:
- socket_address:
address: '${ADAPTER_HOST}'
port_value: '${ADAPTER_PORT}'
http2_protocol_options: {}
transport_socket:
name: envoy.transport_sockets.tls
typed_config:
'@type': >-
type.googleapis.com/envoy.extensions.transport_sockets.tls.v3.UpstreamTlsContext
common_tls_context:
tls_params:
tls_minimum_protocol_version: TLSv1_2
tls_maximum_protocol_version: TLSv1_2
tls_certificates:
private_key:
filename: '${ROUTER_PRIVATE_KEY_PATH}'
certificate_chain:
filename: '${ROUTER_PUBLIC_CERT_PATH}'
validation_context:
trusted_ca:
filename: '${ADAPTER_CA_CERT_PATH}'
- name: ext-authz
type: STRICT_DNS
connect_timeout: 20s
http2_protocol_options: {}
transport_socket:
name: envoy.transport_sockets.tls
typed_config:
'@type': >-
type.googleapis.com/envoy.extensions.transport_sockets.tls.v3.UpstreamTlsContext
common_tls_context:
tls_params:
tls_minimum_protocol_version: TLSv1_2
tls_maximum_protocol_version: TLSv1_2
tls_certificates:
private_key:
filename: '${ROUTER_PRIVATE_KEY_PATH}'
certificate_chain:
filename: '${ROUTER_PUBLIC_CERT_PATH}'
validation_context:
trusted_ca:
filename: '${ENFORCER_CA_CERT_PATH}'
load_assignment:
cluster_name: ext-authz
endpoints:
- lb_endpoints:
- endpoint:
address:
socket_address:
address: '${ENFORCER_HOST}'
port_value: '${ENFORCER_PORT}'

```
**Note**
I have the following observations about the issue.
1. Assert failure does not happen in static configuration. Only in ADS.
2. Assert failure occurs only after deploying an API to envoy. Before deploying I can access config_dump without any issue.
3. Even when I'm not configuring my custom filter from go-control-plane, I'm getting the assert failure. So my guess is the issue got something to do with my filter config. My BUILD file is as follows.

```
api_proto_package(
name = "proto_mgw",
srcs = ["mgw_websocket_rls.proto", "mgw_websocket.proto"],
deps = [
"@envoy_api//envoy/config/ratelimit/v3:pkg",
"@com_github_cncf_udpa//udpa/annotations:pkg",
"@envoy_api//envoy/config/core/v3:pkg",
],
)
```
Any help or tip to solve the issue is highly appreciated since I'm stucked with this for couple of days. I can provide more info too. Thanks