fix: kaniko dir env unused (#2067)
fix: kaniko dir env unused (#2067)

* update kaniko-dir flag description

* add dir check anonymous func for check to config or env

* add kaniko dir constant in default options

* Update cmd/executor/cmd/root.go

Co-authored-by: Jason Hall <54dc689b89cd1edd3b8cc82d44c3d9f567e86e1f@redhat.com>

* add CopyDir util usage for checkKanikoDir func

* add removal of kaniko dir on successful copy of new files

* add comment for CopyDir usage

Co-authored-by: Jason Hall <54dc689b89cd1edd3b8cc82d44c3d9f567e86e1f@redhat.com>
GoogleContainerTools/kaniko,GoogleContainerTools/kaniko,GoogleContainerTools/kaniko