AIP 132: HTTP URI should include a `parent` variable

Version: 1.59.1

Given this method

```protobuf
rpc ListMediaTypes(ListMediaTypesRequest) returns (ListMediaTypesResponse) {
option (google.api.http) = {
get: "/v1/mediaTypes",
additional_bindings: [
{
get: "/v1/{parent=contents/*}/mediaTypes"
},
{
get: "/v1/{parent=contentGroups/*}/mediaTypes"
}
],
};
option (google.api.method_signature) = "parent";
}
```

the aip-linter throws `message: HTTP URI should include a parent variable` while at [AIP-127](https://google.aip.dev/127) under _Multiple URI bindings_ this looks allowed or here https://github.com/googleapis/googleapis/blob/master/google/cloud/resourcemanager/v3/tag_keys.proto#L45C19-L45C37

is this expected? Thank you 🙏