devicemanager test from ubuntu_k8s_unit_tests failed on F-gcp-5.4

Issue found on 5.4.0-1016.16-gcp

Test failed with:
 2020/06/13 17:34:24 Starting to serve on /tmp/mock.sock
 2020/06/13 17:34:24 Starting to serve on /tmp/mock.sock
 2020/06/13 17:34:24 ListAndWatch
 E0613 17:34:24.193574 38091 endpoint.go:106] listAndWatch ended unexpectedly for device plugin mock with error rpc error: code = Canceled desc = grpc: the client connection is closing
 2020/06/13 17:34:24 Starting to serve on /tmp/mock.sock
 2020/06/13 17:34:24 ListAndWatch
 2020/06/13 17:34:24 Allocate, &AllocateRequest{ContainerRequests:[&ContainerAllocateRequest{DevicesIDs:[ADeviceId],}],}
 E0613 17:34:24.195701 38091 endpoint.go:106] listAndWatch ended unexpectedly for device plugin mock with error rpc error: code = Canceled desc = grpc: the client connection is closing
 2020/06/13 17:34:24 Starting to serve on /tmp/device_plugin316746332/device-plugin.sock
 2020/06/13 17:34:24 Starting to serve on /tmp/device_plugin031289355/device-plugin.sock
 E0613 17:34:34.197072 38091 plugin_watcher.go:120] error dial failed at socket /tmp/device_plugin031289355/device-plugin.sock, err: failed to dial socket /tmp/device_plugin031289355/device-plugin.sock, err: context deadline exceeded when handling create event: "/tmp/device_plugin031289355/device-plugin.sock": CREATE
 --- FAIL: TestNewManagerImplStartProbeMode (11.00s)
 manager_test.go:275:
 Error Trace: manager_test.go:275
 manager_test.go:81
 Error: Received unexpected error:
 timeout on stopping watcher
 Test: TestNewManagerImplStartProbeMode
 2020/06/13 17:34:35 Starting to serve on /tmp/device_plugin528138222/device-plugin.sock
 2020/06/13 17:34:35 Deprecation file not found. Invoke registration
 2020/06/13 17:34:35 ListAndWatch
 2020/06/13 17:34:35 Starting to serve on /tmp/device_plugin528138222/device-plugin.sock.new
 2020/06/13 17:34:35 Deprecation file not found. Invoke registration
 2020/06/13 17:34:35 ListAndWatch
 2020/06/13 17:34:35 Starting to serve on /tmp/device_plugin528138222/device-plugin.sock.third
 2020/06/13 17:34:35 Deprecation file not found. Invoke registration
 2020/06/13 17:34:35 ListAndWatch
 E0613 17:34:35.215471 38091 endpoint.go:106] listAndWatch ended unexpectedly for device plugin fake-domain/resource with error rpc error: code = Unavailable desc = transport is closing
 E0613 17:34:35.215588 38091 endpoint.go:106] listAndWatch ended unexpectedly for device plugin fake-domain/resource with error rpc error: code = Canceled desc = grpc: the client connection is closing
 2020/06/13 17:34:35 Starting to serve on /tmp/device_plugin528138222/device-plugin.sock
 2020/06/13 17:34:35 Deprecation file not found. Invoke registration
 E0613 17:34:35.218435 38091 endpoint.go:106] listAndWatch ended unexpectedly for device plugin fake-domain/resource with error rpc error: code = Unavailable desc = transport is closing
 2020/06/13 17:34:35 ListAndWatch
 2020/06/13 17:34:35 Starting to serve on /tmp/device_plugin528138222/device-plugin.sock.new
 2020/06/13 17:34:35 Deprecation file not found. Invoke registration
 2020/06/13 17:34:35 ListAndWatch
 2020/06/13 17:34:35 Starting to serve on /tmp/device_plugin528138222/device-plugin.sock.third
 2020/06/13 17:34:35 Deprecation file not found. Invoke registration
 2020/06/13 17:34:35 ListAndWatch
 E0613 17:34:35.233297 38091 endpoint.go:106] listAndWatch ended unexpectedly for device plugin fake-domain/resource with error rpc error: code = Unavailable desc = transport is closing
 2020/06/13 17:34:35 Starting to serve on /tmp/device_plugin999627539/device-plugin.sock
 E0613 17:34:35.250273 38091 endpoint.go:106] listAndWatch ended unexpectedly for device plugin fake-domain/resource with error rpc error: code = Unavailable desc = transport is closing
 E0613 17:34:35.250343 38091 endpoint.go:106] listAndWatch ended unexpectedly for device plugin fake-domain/resource with error rpc error: code = Unavailable desc = transport is closing
 2020/06/13 17:34:35 GetInfo
 2020/06/13 17:34:35 ListAndWatch
 E0613 17:34:35.251914 38091 plugin_watcher.go:120] error failed to get plugin info using RPC GetInfo at socket /tmp/device_plugin999627539/server.sock, err: rpc error: code = Unimplemented desc = unknown service pluginregistration.Registration when handling create event: "/tmp/device_plugin999627539/server.sock": CREATE
 2020/06/13 17:34:35 Starting to serve on /tmp/device_plugin999627539/device-plugin.sock.new
 2020/06/13 17:34:35 GetInfo
 2020/06/13 17:34:35 ListAndWatch
 2020/06/13 17:34:35 Starting to serve on /tmp/device_plugin999627539/device-plugin.sock.third
 2020/06/13 17:34:35 GetInfo
 2020/06/13 17:34:35 ListAndWatch
 E0613 17:34:35.268727 38091 endpoint.go:106] listAndWatch ended unexpectedly for device plugin fake-domain/resource with error rpc error: code = Unavailable desc = transport is closing