druid 35: protobuf desc loading fails

[gl]

Affected Version

druid 35.0.0, dockerhub official containers

Description

I'm running a druid cluster over managed k8s. A kafka+protobuf spec is working in 34 but failing in 35 (yes I know using 35 was maybe a bit early), due to the protobuf loading:

    "protoBytesDecoder": {
      "type": "file",
      "descriptor": "http://processor-schema/flow.pb.desc",
      "protoMessageType": "FlowMessage"
    }

I tried moving to in-container files (using file:///), but it also fails or inline with base64 (gets a null pointer)

Cannot construct instance of org.apache.druid.data.input.protobuf.FileBasedProtobufBytesDecoder, problem: Descriptor not found in class path [file:///opt/druid/flow.pb.desc]

with inline: Cannot construct instance of org.apache.druid.data.input.protobuf.InlineDescriptorProtobufBytesDecoder, problem: java.lang.NullPointerException

So there's something quite not right that looks like a regression.

No issues up to druid-34, I reverted and everthing worked appropriately.

I don't need druid 35 so no hurry for me but I thought you may want to know.