Possible states of the batch processing operation.
Values:
STATE_UNSPECIFIED (0):
The default value. This value is used if the
state is omitted.
WAITING (1):
Request operation is waiting for scheduling.
RUNNING (2):
Request is being processed.
SUCCEEDED (3):
The batch processing completed successfully.
CANCELLING (4):
The batch processing was being cancelled.
CANCELLED (5):
The batch processing was cancelled.
FAILED (6):
The batch processing has failed.