Automatic merge from submit-queue (batch tested with PRs 61962, 58972, 62509, 62606). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Avoid data races in unit tests

Setting global flags in unit tests leads to data races like this:

```
==================
WARNING: DATA RACE
Write at 0x0000028f5241 by goroutine 47:
  flag.(*boolValue).Set()
      /home/jliggitt/.gvm/gos/go1.9.5/src/flag/flag.go:91 +0x7b
  flag.(*FlagSet).Set()
      /home/jliggitt/.gvm/gos/go1.9.5/src/flag/flag.go:366 +0x10c
  flag.Set()
      /home/jliggitt/.gvm/gos/go1.9.5/src/flag/flag.go:379 +0x76
  k8s.io/kubernetes/pkg/kubelet/cm/devicemanager.TestPodContainerDeviceAllocation()
      /home/jliggitt/go/src/k8s.io/kubernetes/pkg/kubelet/cm/devicemanager/manager_test.go:549 +0x126
  testing.tRunner()
      /home/jliggitt/.gvm/gos/go1.9.5/src/testing/testing.go:746 +0x16c

Previous read at 0x0000028f5241 by goroutine 34:
  k8s.io/kubernetes/vendor/github.com/golang/glog.(*loggingT).output()
      /home/jliggitt/go/src/k8s.io/kubernetes/vendor/github.com/golang/glog/glog.go:682 +0x730
  k8s.io/kubernetes/vendor/github.com/golang/glog.(*loggingT).printf()
      /home/jliggitt/go/src/k8s.io/kubernetes/vendor/github.com/golang/glog/glog.go:655 +0x259
  k8s.io/kubernetes/vendor/github.com/golang/glog.Errorf()
      /home/jliggitt/go/src/k8s.io/kubernetes/vendor/github.com/golang/glog/glog.go:1118 +0x74
  k8s.io/kubernetes/pkg/kubelet/cm/devicemanager.(*endpointImpl).run()
      /home/jliggitt/go/src/k8s.io/kubernetes/pkg/kubelet/cm/devicemanager/endpoint.go:132 +0x1c7e
  k8s.io/kubernetes/pkg/kubelet/cm/devicemanager.(*ManagerImpl).addEndpoint.func1()
      /home/jliggitt/go/src/k8s.io/kubernetes/pkg/kubelet/cm/devicemanager/manager.go:378 +0x3f

Goroutine 47 (running) created at:
  testing.(*T).Run()
      /home/jliggitt/.gvm/gos/go1.9.5/src/testing/testing.go:789 +0x568
  testing.runTests.func1()
      /home/jliggitt/.gvm/gos/go1.9.5/src/testing/testing.go:1004 +0xa7
  testing.tRunner()
      /home/jliggitt/.gvm/gos/go1.9.5/src/testing/testing.go:746 +0x16c
  testing.runTests()
      /home/jliggitt/.gvm/gos/go1.9.5/src/testing/testing.go:1002 +0x521
  testing.(*M).Run()
      /home/jliggitt/.gvm/gos/go1.9.5/src/testing/testing.go:921 +0x206
  main.main()
      k8s.io/kubernetes/pkg/kubelet/cm/devicemanager/_test/_testmain.go:68 +0x1d3

Goroutine 34 (finished) created at:
  k8s.io/kubernetes/pkg/kubelet/cm/devicemanager.(*ManagerImpl).addEndpoint()
      /home/jliggitt/go/src/k8s.io/kubernetes/pkg/kubelet/cm/devicemanager/manager.go:377 +0x9d6
==================
--- FAIL: TestPodContainerDeviceAllocation (0.00s)
	testing.go:699: race detected during execution of test
FAIL
FAIL	k8s.io/kubernetes/pkg/kubelet/cm/devicemanager	0.124s

```