add periodic job to run e2e test for istio upgrade command (#1948)
add periodic job to run e2e test for istio upgrade command (#1948)

* add periodic job to run e2e test for istio upgrade command

* fix lint error

* fix json unmarshal issue

* change the branch name to master

istio/test-infra,istio/test-infra,istio/test-infra,istio/test-infra