Update gRPC Auth config (#4061)

Update gRPC Auth config so that, if no headers are
specified in `allowedHeaders`, _all_ headers must
be sent rather than a specific list.

Signed-off-by: Nick Young <[email protected]>

Author: youngnick

apis/v1/httproute_types.go

@@ -1665,13 +1665,7 @@ type GRPCAuthConfig struct {
 	// AllowedRequestHeaders specifies what headers from the client request
 	// will be sent to the authorization server.
 	//
-	// If this list is empty, then the following headers must be sent:
-	//
-	// - `Authorization`
-	// - `Location`
-	// - `Proxy-Authenticate`
-	// - `Set-Cookie`
-	// - `WWW-Authenticate`
+	// If this list is empty, then all headers must be sent.
 	//
 	// If the list has entries, only those entries must be sent.
 	//