[Feature Request] Add podDisruptionBudget in API server

[MuhtasimTanmoy]

Description

Closes #2886

This PR adds podDisruptionBudget in the API Server and affects the calico-apiserver component.

Testing

For testing this feature :

1. Install operator
2. Run kubectl create -f ./config/samples/operator_v1_apiserver.yaml
3. Run kubectl -n calico-system get pdb
4. Shows podDisruptionBudget for calico-apiserver component.

For PR author

• Tests for change.
• If changing pkg/apis/, run make gen-files
• If changing versions, run make gen-versions

For PR reviewers

A note for code reviewers - all pull requests must have the following:

• Milestone set according to targeted release.
• Appropriate labels:
  • kind/bug if this is a bugfix.
  • kind/enhancement if this is a new feature.
  • enterprise if this PR applies to Calico Enterprise only.

[CLAassistant]

All committers have signed the CLA.

[caseydavenport]

@MuhtasimTanmoy thanks for the PR! I've left a couple of small comments on it.

[caseydavenport]

/sem-approve

[caseydavenport]

@MuhtasimTanmoy looks like make ut is failing because it's not expecting this new resource to exist.

Here's an example failure:

pkg/render Suite
Failure
/go/src/github.com/tigera/operator/pkg/render/apiserver_test.go:1653
Expected
    <int>: 16
to equal
    <int>: 15
/go/src/github.com/tigera/operator/pkg/render/apiserver_test.go:1568

You should be able to run these locally with make ut

[tmjd]

I've pushed a commit to this branch, I found one bit I think needed changing (I've put a comment there) and I've fixed up the unit tests, they passed for me locally.

[tmjd]

/sem-approve