This is a repackage of implementation https://issues.apache.org/jira/browse/SPARK-28120, RocksDB state storage, in order to use it with current spark 2.4.x release.
- Use "sbt package" to build jar, copy the jar file and rocksdbjni.jar to spark library
- Let spark to use the it, by set "spark.sql.streaming.stateStore.providerClass" to "org.apache.spark.sql.execution.streaming.state.rocksdb.RocksDbStateStoreProvider"
[Original Pull request] (apache/spark#24922)