Values:
EXECUTION_REASON_UNDEFINED (0):
Default value.
JOB_STATUS_SERVICE_POLLING_ERROR (1):
Internal system error getting execution
status. System will retry.
NON_ZERO_EXIT_CODE (2):
A task reached its retry limit and the last
attempt failed due to the user container exiting
with a non-zero exit code.
CANCELLED (3):
The execution was cancelled by users.
CANCELLING (4):
The execution is in the process of being
cancelled.
