Description
I noticed that the hive.metastore.token.signature property is not defined in HiveConf.java, but hardcoded everywhere it's used in the Hive codebase.
HIVE-2963 fixes this but was never committed due to being resolved as a duplicate ticket.
We should add hive.metastore.token.signature to HiveConf.java to centralize its definition and make the property more discoverable (it's useful to set it when talking to multiple metastores).