Automatic merge from submit-queue (batch tested with PRs 41794, 42349, 42755, 42901, 42933)

Fix DefaultTolerationSeconds admission plugin

DefaultTolerationSeconds is not working as expected. It is supposed to add default tolerations (for unreachable and notready conditions). but no pod was getting these toleration. And api server was throwing this error:

```
Mar 08 13:43:57 fedora25 hyperkube[32070]: E0308 13:43:57.769212   32070 admission.go:71] expected pod but got Pod
Mar 08 13:43:57 fedora25 hyperkube[32070]: E0308 13:43:57.789055   32070 admission.go:71] expected pod but got Pod
Mar 08 13:44:02 fedora25 hyperkube[32070]: E0308 13:44:02.006784   32070 admission.go:71] expected pod but got Pod
Mar 08 13:45:39 fedora25 hyperkube[32070]: E0308 13:45:39.754669   32070 admission.go:71] expected pod but got Pod
Mar 08 14:48:16 fedora25 hyperkube[32070]: E0308 14:48:16.673181   32070 admission.go:71] expected pod but got Pod
```

The reason for this error is that the input to admission plugins is internal api objects not versioned objects so expecting versioned object is incorrect. Due to this, no pod got desired tolerations and it always showed:

```
Tolerations: <none>
```

After this fix, the correct  tolerations are being assigned to pods as follows:

```
Tolerations:	node.alpha.kubernetes.io/notReady=:Exists:NoExecute for 300s
		node.alpha.kubernetes.io/unreachable=:Exists:NoExecute for 300s
```

@davidopp @kevin-wangzefeng @kubernetes/sig-scheduling-pr-reviews @kubernetes/sig-scheduling-bugs @derekwaynecarr 

Fixes https://github.com/kubernetes/kubernetes/issues/42716