rwcore - RPC update-flows-incrementally() triggered during reconciling

Found in https://jenkins.opencord.org/view/All%20Jobs/job/periodic-voltha-multiple-olts-openonu-go-test-bbsim/292/:

Despite the fact that ONU-adapter has set "voltha.OperStatus_RECONCILING" by calling CoreProxy::DeviceStateUpdate() to indicate an active reconciling process, rwcore triggers the RPC "update-flows-incrementally()" towards the ONU-adapter.

RPC: reconcile-device():
voltha/voltha-voltha-adapter-openonu-6b79d4f567-scrqp[adapter-open-onu]:

{"level":"info","ts":"2021-06-17T11:43:18.601Z","caller":"onuadaptercore/openonu.go:329","msg":"reconcile-device","instanceId":"voltha-voltha-adapter-openonu-6b79d4f567-scrqp","pkg":"adaptercoreonu","device-id":"77424469-f357-4e3f-b811-f078758056cb"}

...
DeviceStateUpdate(voltha.OperStatus_RECONCILING):
voltha/voltha-voltha-adapter-openonu-6b79d4f567-scrqp[adapter-open-onu]:

{"level":"debug","ts":"2021-06-17T11:43:18.606Z","caller":"common/core_proxy.go:296","msg":"DeviceStateUpdate","instanceId":"voltha-voltha-adapter-openonu-6b79d4f567-scrqp","device-id":"77424469-f357-4e3f-b811-f078758056cb"}

...
start reconciling():
voltha/voltha-voltha-adapter-openonu-6b79d4f567-scrqp[adapter-open-onu]:

{"level":"debug","ts":"2021-06-17T11:43:18.615Z","caller":"onuadaptercore/device_handler.go:3530","msg":"start reconciling","instanceId":"voltha-voltha-adapter-openonu-6b79d4f567-scrqp","pkg":"adaptercoreonu","device-id":"77424469-f357-4e3f-b811-f078758056cb","skipOnuConfig":false}

...
RPC: update-flows-incrementally()
voltha/voltha-voltha-adapter-openonu-6b79d4f567-scrqp[adapter-open-onu]:

{"level":"info","ts":"2021-06-17T11:43:19.300Z","caller":"onuadaptercore/openonu.go:452","msg":"update-flows-incrementally","instanceId":"voltha-voltha-adapter-openonu-6b79d4f567-scrqp","pkg":"adaptercoreonu","device-id":"77424469-f357-4e3f-b811-f078758056cb"}

...
flow-add rejected due to improper device state:
voltha/voltha-voltha-adapter-openonu-6b79d4f567-scrqp[adapter-open-onu]:

{"level":"error","ts":"2021-06-17T11:43:19.300Z","caller":"onuadaptercore/device_handler.go:715","msg":"flow-add rejected: improper device state","instanceId":"voltha-voltha-adapter-openonu-6b79d4f567-scrqp","pkg":"adaptercoreonu","device-id":"77424469-f357-4e3f-b811-f078758056cb","last device-reason":"discovery-mibsync-complete","stacktrace":"github.com/opencord/voltha-lib-go/v4/pkg/log.clogger.Errorw\n\t/go/src/vendor/github.com/opencord/voltha-lib-go/v4/pkg/log/log.go:612\ngithub.com/opencord/voltha-openonu-adapter-go/internal/pkg/onuadaptercore.(*deviceHandler).FlowUpdateIncremental\n\t/go/src/internal/pkg/onuadaptercore/device_handler.go:715\ngithub.com/opencord/voltha-openonu-adapter-go/internal/pkg/onuadaptercore.(*OpenONUAC).Update_flows_incrementally\n\t/go/src/internal/pkg/onuadaptercore/openonu.go:470\ngithub.com/opencord/voltha-lib-go/v4/pkg/adapters/common.(*RequestHandlerProxy).Update_flows_incrementally\n\t/go/src/vendor/github.com/opencord/voltha-lib-go/v4/pkg/adapters/common/request_handler.go:401\nreflect.Value.call\n\t/usr/local/go/src/reflect/value.go:476\nreflect.Value.Call\n\t/usr/local/go/src/reflect/value.go:337\ngithub.com/opencord/voltha-lib-go/v4/pkg/kafka.CallFuncByName\n\t/go/src/vendor/github.com/opencord/voltha-lib-go/v4/pkg/kafka/kafka_inter_container_library.go:765\ngithub.com/opencord/voltha-lib-go/v4/pkg/kafka.(*interContainerProxy).handleMessage\n\t/go/src/vendor/github.com/opencord/voltha-lib-go/v4/pkg/kafka/kafka_inter_container_library.go:892"}

...
stop reconciling():
voltha/voltha-voltha-adapter-openonu-6b79d4f567-scrqp[adapter-open-onu]:

{"level":"debug","ts":"2021-06-17T11:43:20.101Z","caller":"onuadaptercore/device_handler.go:3592","msg":"stop reconciling","instanceId":"voltha-voltha-adapter-openonu-6b79d4f567-scrqp","pkg":"adaptercoreonu","device-id":"77424469-f357-4e3f-b811-f078758056cb"}