Use dynamic client to get annotations

[Monokaix]

What type of PR is this?

/kind cleanup
/area controllers

What this PR does / why we need it:

Use dynamic client instead of swich case.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

None

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[hwdef]

There may be performance issues with dynamic client.
We'd better run a performance test.

[Monokaix]

There may be performance issues with dynamic client. We'd better run a performance test.

That's a good point.