ceph: wait for cainjector to inject the CA certificates

adding 20s sleep to let cainjector to inject the CA
certificates into cert-manager webhook.

Signed-off-by: subhamkrai <srai@redhat.com>

tests/scripts/deploy_admission_controller.sh

@@ -54,6 +54,7 @@ echo "Deploying cert-manager"
 kubectl apply -f https://github.com/jetstack/cert-manager/releases/download/$CERT_VERSION/cert-manager.yaml
 timeout 150 sh -c 'until [ $(kubectl -n cert-manager get pods --field-selector=status.phase=Running|grep -c ^cert-) -eq 3 ]; do sleep 1; done'
 timeout 20 sh -c 'until [ $(kubectl -n cert-manager get pods -o custom-columns=READY:status.containerStatuses[*].ready | grep -c true) -eq 3 ]; do sleep 1; done'
+sleep 20
 
 echo "Successfully deployed cert-manager"