Wrong raisedTs in voltha event

Voltha events from openonu-go-adpter for PM-data contain a wrong 'raisedTs', 'reportedTs is correct.

Example (printout of voltctl):

{
"header": {
"id": "Voltha.openolt..1619017047664319168",
"category": "EQUIPMENT",
"subCategory": "ONU",
"type": "KPI_EVENT2",
"typeVersion": "0.1",
"raisedTs": "1970-01-01T00:00:01.619017047Z",
"reportedTs": "2021-04-21T14:57:27.664320677Z"
},
"kpiEvent2": {
"type": "slice",
"ts": 1619017047,
"sliceData": [
{
"metadata": {
"title": "PON_Optical",
"ts": 1619017047,
"logicalDeviceId": "dc6ae00a-98a3-4d5b-bcaf-f01126b7bb13",
"serialNo": "BBSM000a0001",
"deviceId": "dc6ae00a-98a3-4d5b-bcaf-f01126b7bb13",
"context":

{ "devicetype": "brcm_openomci_onu", "intfID": "0", "onuID": "1" }

,
"uuid": ""
},
"metrics":

{ "ani_g_instance_id": 32769, "receive_power_dBm": 7.7, "transmit_power_dBm": 7.5 }

}
]
}
}

It seems to be raisedTs is shifted, because seconds since epoch visible as the '1' of seconds + 'nanos':

"raisedTs": "1970-01-01T00:00:0*1.619017047*Z"