INK-214: log.inkless.enable should only apply to non-internal topics.

[gharris1727]

This is a bug introduced in #251 that causes internal topics (such as __consumer_offsets) to be created as inkless topics when log.inkless.enable is specified. Some integration tests explicitly create these internal topics, and trigger this behavior.

[jeqo]

I was troubleshooting this as well while trying to deploy this change to Aiven core: as there are many brokers there and consumer offsets topic has 3 replicas the topic never creates as Inkless topics cannot have more than 1 replica.
This is not enough to disable inkless on internal topics: it's only useful for the topic provisioning but the response and configuration stored in KRaft is still with inkless enabled because the broker default is true.

I found these two additional changes to be needed:

For the response building:

            for (String configName : configNames) {
                ConfigEntry entry = effectiveConfig.get(configName);
                String value = entry.isSensitive() ? null : entry.value();
                // Set response with inkless disabled on all internal topics
                if (Topic.isInternal(topic.name()) && configName.equals(INKLESS_ENABLE_CONFIG)) {
                    value = String.valueOf(false);
                }
                result.configs().add(new CreateTopicsResponseData.CreatableTopicConfigs().
                    setName(entry.name()).
                    setValue(value).
                    setReadOnly(entry.isReadOnly()).
                    setConfigSource(KafkaConfigSchema.translateConfigSource(entry.source()).id()).
                    setIsSensitive(entry.isSensitive()));
            }

And for the records to be stored

        records.add(new ApiMessageAndVersion(new TopicRecord().
            setName(topic.name()).
            setTopicId(topicId), (short) 0));
        // ConfigRecords go after TopicRecord but before PartitionRecord(s).
        // Disable inkless on all internal topics on the configs to be stored
        if (Topic.isInternal(topic.name())) {
            configRecords.add(new ApiMessageAndVersion(new ConfigRecord()
                .setName(INKLESS_ENABLE_CONFIG)
                .setValue("false")
                .setResourceName(topic.name())
                .setResourceType(ResourceType.TOPIC.code()), (short) 0));
        }
        records.addAll(configRecords);

Would be great to extend tests to cover these scenarios as well.

[jeqo]

I created #268 to unblock aiven-core.