Implement generated files snapshot test for kubernetes.

[mshima]

Deployment test suites currently tests:

• generated file names.
• a few generated contents.

There is no real execution tests and generated contents coverage is too low.

This PR implements generated files snapshot tests for kubernetes.

• A full generated content regression test.

Old tests are kept for now but could be dropped.

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[mshima]

@Tcharl, with this we can merge #14767 with confidence.

After merged, I will migrate others deployment test to snapshot.

[Tcharl]

Looks correct :-). I get your point @mshima , to be honest I generated and regenerated my PR with the different options, but even with that my knees are knocking

@mshima should I merge?

[atomfrede]

@mshima Looks good. Can you resolve the conflicts?

[mshima]

2 positive reviews, merged.