http: adding an option to preserve hop by hop headers (#17110)

Risk Level: low (config guarded code)
Testing: new unit tests
Docs Changes: n/a
Release Notes: intentionally not added
Platform Specific Features: n/a
Part of envoyproxy/envoy-mobile#1540
Signed-off-by: Alyssa Wilk <alyssar@chromium.org>

Mirrored from https://github.com/envoyproxy/envoy @ 8589ca86a4e937a57206b9be85d7faa9e8f0ca3d

envoy/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto

@@ -1005,3 +1005,11 @@ message RequestIDExtension {
   // Request ID extension specific configuration.
   google.protobuf.Any typed_config = 1;
 }
+
+// [#protodoc-title: Envoy Mobile HTTP connection manager]
+// HTTP connection manager for use in Envoy mobile.
+message EnvoyMobileHttpConnectionManager {
+  // The configuration for the underlying HttpConnectionManager which will be
+  // instantiated for Envoy mobile.
+  HttpConnectionManager config = 1;
+}

envoy/extensions/filters/network/http_connection_manager/v4alpha/http_connection_manager.proto

@@ -990,3 +990,15 @@ message RequestIDExtension {
   // Request ID extension specific configuration.
   google.protobuf.Any typed_config = 1;
 }
+
+// [#protodoc-title: Envoy Mobile HTTP connection manager]
+// HTTP connection manager for use in Envoy mobile.
+message EnvoyMobileHttpConnectionManager {
+  option (udpa.annotations.versioning).previous_message_type =
+      "envoy.extensions.filters.network.http_connection_manager.v3."
+      "EnvoyMobileHttpConnectionManager";
+
+  // The configuration for the underlying HttpConnectionManager which will be
+  // instantiated for Envoy mobile.
+  HttpConnectionManager config = 1;
+}