adding cainjection file validation check

[jpflueger]

Closes #1119

What this PR does / why we need it:
Adds a validation check to the pipeline to enforce the cainjection patch annotations for certmanager.

Special notes for your reviewer:
Change the annotation in a file like config/crd/patches/cainjection_in_rediscacheactions.yaml to be:

# The following patch adds a directive for certmanager to inject CA into the CRD
# CRD conversion requires k8s 1.13 or later.
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
  annotations:
    certmanager.k8s.io/inject-ca-from: $(CERTIFICATE_NAMESPACE)/$(CERTIFICATE_NAME)
  name: rediscacheactions.azure.microsoft.com

And then run make validate-cainjection-files to see the output.

The pipeline in this PR will fail intentionally until PR #1124 is merged in.

How does this PR make you feel:

[jananivMS]

Looks good to me.

[jananivMS]

@jpflueger The changes look good but lets wait for the other PR to be merged before merging this to avoid pipeline failures

[jananivMS]

Looks good