Clean succeeds for PDB even as PDB staus is UNABLE to OFFLINE

Oracle does not allow any operation on a PDB when the PDB is in backup mode. This is an expected behavior of Oracle. Therefore, a shutdown fails when it is initiated on a PDB in backup mode and returns an UNABLE TO OFFLINE status for the PDB. If PDB is removed from the backup mode using the SQL script, the agent framework is unable to change the UNABLE TO OFFLINE status of the PDB as clean is called. Since Oracle does not differntiate between clean and offline for PDB, clean succeeds for the PDB in spite of being in UNABLE TO OFFLINE state.

Workaround: No workaround.