Oracle Database - 12c - Data Pump Error during ORA-1031 during export of SYS tables

Issue occurs when you do a full export of your 12c (mine is 12.1.0.2) database with export of few SYS tables. 
This is when you do a consistent export using flashback_time or flashback_scn parameter
Even if you have the role - DATAPUMP_EXP_FULL_DATABASE

when you scan your log file, you will see multiple errors similar to below -

ORA-31693: Table data object "SYS"."KU$_USER_MAPPING_VIEW" failed to load/unload and is being skipped due to error:

ORA-01031: insufficient privileges

ORA-31693: Table data object "SYS"."FGA_LOG$FOR_EXPORT" failed to load/unload and is being skipped due to error:

ORA-01031: insufficient privileges

ORA-31693: Table data object "SYS"."AUDTAB$TBS$FOR_EXPORT" failed to load/unload and is being skipped due to error:

ORA-01031: insufficient privileges

ORA-31693: Table data object "SYS"."DBA_SENSITIVE_DATA" failed to load/unload and is being skipped due to error:

ORA-01031: insufficient privileges

ORA-31693: Table data object "SYS"."DBA_TSDP_POLICY_PROTECTION" failed to load/unload and is being skipped due to error:

ORA-01031: insufficient privileges

ORA-31693: Table data object "SYS"."NACL$_ACE_EXP" failed to load/unload and is being skipped due to error:

ORA-01031: insufficient privileges

ORA-31693: Table data object "SYS"."NACL$_HOST_EXP" failed to load/unload and is being skipped due to error:

ORA-01031: insufficient privileges

ORA-31693: Table data object "SYS"."NACL$_WALLET_EXP" failed to load/unload and is being skipped due to error:

ORA-01031: insufficient privileges

The workaround is to grant flashback to the tables reporting errors 

SQL> grant flashback on "SYS"."KU$_USER_MAPPING_VIEW"  to system;
Grant succeeded.

SQL> grant flashback on "SYS"."FGA_LOG$FOR_EXPORT" to system;
Grant succeeded.

SQL> grant flashback on  "SYS"."AUDTAB$TBS$FOR_EXPORT" to system;
Grant succeeded.

SQL> grant flashback on "SYS"."DBA_SENSITIVE_DATA"  to system;
Grant succeeded.

SQL> grant flashback on  "SYS"."DBA_TSDP_POLICY_PROTECTION" to system;
Grant succeeded.

SQL> grant flashback on  "SYS"."NACL$_ACE_EXP" to system;
Grant succeeded.

SQL> grant flashback on  "SYS"."NACL$_HOST_EXP"to system;
Grant succeeded.

SQL> grant flashback on "SYS"."NACL$_WALLET_EXP"  to system;
Grant succeeded.

The issue and workaround is reported in Bug - 18844843