PAI training service: EARLY stopped trial job status is "USER_CANCELED"

[chicm-ms]

assessor: median stop
maxTrialNum: 8
trialConcurrency: 8

This problem has been reproduced on PAI IT pipeline multiple times.

[3/22/2020, 1:42:46 AM] INFO [ 'NNIManager received command from dispatcher: KI, "pVTgC"' ]
[3/22/2020, 1:42:46 AM] INFO [ 'cancelTrialJob: pVTgC' ]
[3/22/2020, 1:42:46 AM] INFO [ 'POST: /stdout/tL9oppaY/pVTgC: body:\n{\n    "tag": "trial",\n    "stdOutputType": "Stdout",\n    "msg": "NNISDK_MEb\'{\\"sequence\\": 17, \\"parameter_id\\": 4, \\"trial_job_id\\": \\"pVTgC\\", \\"value\\": \\"-0.7386407815195938\\", \\"type\\": \\"PERIODICAL\\"}\'"\n}' ]
[3/22/2020, 1:42:46 AM] INFO [ 'NNIManager received command from dispatcher: KI, "pVTgC"' ]
[3/22/2020, 1:42:46 AM] INFO [ 'cancelTrialJob: pVTgC' ]
[3/22/2020, 1:42:47 AM] INFO [ 'POST: /stdout/tL9oppaY/pVTgC: body:\n{\n    "tag": "trial",\n    "stdOutputType": "Stdout",\n    "msg": "NNISDK_MEb\'{\\"sequence\\": 18, \\"parameter_id\\": 4, \\"trial_job_id\\": \\"pVTgC\\", \\"value\\": \\"-0.8328627067207651\\", \\"type\\": \\"PERIODICAL\\"}\'"\n}' ]
[3/22/2020, 1:42:47 AM] INFO [ 'NNIManager received command from dispatcher: KI, "pVTgC"' ]
[3/22/2020, 1:42:47 AM] INFO [ 'cancelTrialJob: pVTgC' ]
[3/22/2020, 1:42:47 AM] INFO [ 'POST: /stdout/tL9oppaY/pVTgC: body:\n{\n    "tag": "trial",\n    "stdOutputType": "Stdout",\n    "msg": "NNISDK_MEb\'{\\"sequence\\": 19, \\"parameter_id\\": 4, \\"trial_job_id\\": \\"pVTgC\\", \\"value\\": \\"-0.9026275312848\\", \\"type\\": \\"PERIODICAL\\"}\'"\n}' ]
[3/22/2020, 1:42:47 AM] INFO [ 'NNIManager received command from dispatcher: KI, "pVTgC"' ]
[3/22/2020, 1:42:47 AM] INFO [ 'cancelTrialJob: pVTgC' ]
[3/22/2020, 1:42:47 AM] INFO [ 'Trial job pVTgC status changed from RUNNING to USER_CANCELED' ]
[3/22/2020, 1:42:47 AM] INFO [ 'Trial job CNDTO status changed from WAITING to RUNNING' ]

[SparkSnail]

This issue is caused by PAI status update error, when job in PAI is in 'STOPPING' status, NNI client does parse this status correctly, and set trial to USER_CANCELED.
Fix in #2229