Fixed Issues in Schema Registry

Review the list of Schema Registry issues that are resolved in Cloudera Runtime 7.1.8.

CDPD-41592: Confluent import should handle input without an actual version
Lines ignored in Confluent import format where only the first part corresponding to a Cloudera SR "meta" is present and schema version data is missing (or only a "null" string is there).
CDPD-40758: Improve upon how SchemaRegistryClient is used in connectors
Fixed the issue when setting the "value.converter.serdes.protocol.version" in connectors caused the connector to fail on startup because the configuration property wasn't properly converted to a byte value.
CDPD-39885: SchemaRegistryResource.uploadFiles fails w/ Timeout waiting for connection from pool
When downloading a file from Schema Registry, the stream was not properly closed which occasionally caused issues. This has been fixed by always closing the stream.
CDPD-35983: Unique constraint violation on load balanced SR cluster startup
A concurrency issue in a multi node SR setup was fixed where more nodes tried to initialize database state at the same time causing some of them to fail.
CDPD-35469: SR responds with Internal Server Error when adding more schemas than defined in offset range
Schema Registry responds with HTTP 409 response instead of HTTP 500 response when trying to add more schemas than defined in offset range.
OPSAPS-61017: Ranger SchemaRegistry Plugin Audit Directory is not created when upgrading to 7.4.2+
When upgrading from earlier versions to 7.1.7/7.2.9 with existing Schema Registry service, hdfsDirs will automatically be created; affects CM >= 7.5.1.