Remove unnecessary prefixes from various .import-restrictions files

Found using script:
https://gist.github.com/dims/384dea60754042f61d79233603034038

Just run using:
`find . -name .import-restrictions | xargs python ~/junk/sanitize-import-boss.py`

The removed entries are either packages that got moved/renamed/deleted
but are still not cleaned up from .import-restrictions files.

Change-Id: I92c400f74e6f012cc75539311ed4de280e25e918

pkg/client/clientset_generated/.import-restrictions

@@ -3,7 +3,6 @@
     {
       "SelectorRegexp": "k8s[.]io/kubernetes/pkg/client/unversioned",
       "AllowedPrefixes": [
-        "k8s.io/kubernetes/pkg/client/unversioned/clientcmd/api"
       ]
     }
   ]