fix VI cats

Summary:
Details on "why": https://fb.workplace.com/groups/2071217289839797/permalink/3401769186784594/

We need to forward these CAT tokens to verify integrity service. Now that we have the land service, we need to forward those CATs also through the land service.

We do that in `get_service_client` called here:
https://www.internalfb.com/code/fbsource/[27503e0eb5ead5894dd3d8c4bfb9b0040c915bca]/fbcode/eden/mononoke/pushrebase/client/facebook/land_service.rs?lines=257

The `get_service_client` in its body has:
https://www.internalfb.com/code/fbsource/[e0f913f7c3b93921f058dc6bd3d11a4d11b3c592]/fbcode/eden/mononoke/common/facebook/thrift_client/src/lib.rs?lines=129-135

Reviewed By: zzl0

Differential Revision: D66599190

fbshipit-source-id: 41359562f4886fe86d3b4782074341d8fa324748

eden/mononoke/gotham_ext/src/middleware/metadata.rs

@@ -39,6 +39,7 @@ const ENCODED_CLIENT_IDENTITY: &str = "x-fb-validated-client-encoded-identity";
 const CLIENT_IP: &str = "tfb-orig-client-ip";
 const CLIENT_PORT: &str = "tfb-orig-client-port";
 const HEADER_REVPROXY_REGION: &str = "x-fb-revproxy-region";
+const HEADER_FORWARDED_CATS: &str = "x-forwarded-cats";
 
 #[derive(StateData, Default)]
 pub struct MetadataState(Metadata);
@@ -150,6 +151,13 @@ impl Middleware for MetadataMiddleware {
             if let Some(revproxy_region) = revproxy_region_from_headers(headers) {
                 metadata.add_revproxy_region(revproxy_region);
             }
+            if let Some(vi_cats) = headers
+                .get(HEADER_FORWARDED_CATS)
+                .and_then(|x| x.to_str().ok())
+                .map(|x| x.to_string())
+            {
+                metadata.add_raw_encoded_cats(vi_cats);
+            }
 
             let maybe_identities = if self.mtls_disabled {
                 ingress_request_identities_from_headers(headers)