feat: scrub fields with ResourceDescriptor type

Since we have already scrubbed away the proto file descriptor for this
type, we also need to scrub away any fields that refer to this type.

main.go

@@ -35,6 +35,7 @@ func main() {
 			scrubResource(message)
 			scrubResourceReferences(message)
 			scrubFieldBehaviors(message)
+			scrubMessageFields(message)
 		}
 		for _, service := range file.GetService() {
 			scrubServiceOptions(service)
@@ -86,6 +87,20 @@ func scrubServiceOptions(service *descriptorpb.ServiceDescriptorProto) {
 	}
 }
 
+func scrubMessageFields(message *descriptorpb.DescriptorProto) {
+	n := 0
+	for _, field := range message.Field {
+		if field.GetTypeName() != ".google.api.ResourceDescriptor" {
+			message.Field[n] = field
+			n++
+		}
+	}
+	message.Field = message.Field[:n]
+	for _, nestedMessage := range message.NestedType {
+		scrubMessageFields(nestedMessage)
+	}
+}
+
 func scrubResourceReferences(message *descriptorpb.DescriptorProto) {
 	for _, field := range message.GetField() {
 		if field.GetOptions() != nil {