[Kubernetes] Add system testing for state service

[constanca-m]

What does this PR do?

Add system testing for state service datastream.

Unlike the other state_* datastreams, the _dev folder needed for that test was missing.

[MichaelKatsoulis]

Thanks @constanca-m !
Update also the manifest and changelog file of kubernetes package. I suggest to increase the patch version

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• Start Time: 2023-02-01T15:37:11.755+0000

• Duration: 28 min 56 sec

Test stats 🧪

Test	Results
Failed	0
Passed	92
Skipped	0
Total	92

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Name	Metrics % (covered/total)	Diff
Packages	100.0% (0/0)	💚
Files	100.0% (0/0)	💚
Classes	100.0% (0/0)	💚
Methods	96.154% (75/78)	👍 10.44
Lines	100.0% (0/0)	💚 6.618
Conditionals	100.0% (0/0)	💚

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Package kubernetes - 1.31.2 containing this change is available at https://epr.elastic.co/search?package=kubernetes