Let users define tracing options in all cases

[tsegismont]

When creating a producer/consumer (or the stream equivalent) from an existing Kafka client producer/consumer, default tracing options where used.

Consequently, the policy was always set to PROPAGATE.

Besides, when creating a shared producer, user provided config was used to create the Kafka producer, but then default options were used for tracing.

[tsegismont]

Thanks @ppatierno