[202205][Auto-Techsupport] Fix the coredump_gen_handler Exception when the History table is empty (#2265)

[stepanblyschak]

What I did

BACKPORT OF: #2265

coredump_gen_handler script is throwing exception currently when the history table is empty.

root@r-lionfish-14:/home/admin# cat /tmp/coredump_gen_handler.log
Traceback (most recent call last):
  File "/usr/local/bin/coredump_gen_handler.py", line 82, in <module>
    main()
  File "/usr/local/bin/coredump_gen_handler.py", line 77, in main
    cls.handle_core_dump_creation_event()
  File "/usr/local/bin/coredump_gen_handler.py", line 60, in handle_core_dump_creation_event
    invoke_ts_command_rate_limited(self.db, EVENT_TYPE_CORE, {CORE_DUMP: self.core_name}, self.container)
  File "/usr/local/lib/python3.9/dist-packages/utilities_common/auto_techsupport_helper.py", line 331, in invoke_ts_command_rate_limited
    cooloff_passed = verify_rate_limit_intervals(db, global_cooloff, container_cooloff, container)
  File "/usr/local/lib/python3.9/dist-packages/utilities_common/auto_techsupport_helper.py", line 291, in verify_rate_limit_intervals
    if container_cooloff and container in ts_map:
TypeError: argument of type 'NoneType' is not iterable

How I did it

How to verify it

Previous command output (if the output of a command-line utility has changed)

New command output (if the output of a command-line utility has changed)