CI: K8sUpdateTest handles pre-existing cilium-preflight pods
CI: K8sUpdateTest handles pre-existing cilium-preflight pods

Since we use helm install in the update/upgrade test, preflight isn't
expected to be running. When we re-run a failed test, this triggers a
helm error.

Similarly, whatever agent.image is set to during cleanup
should also be the value for preflight. It is now set appropriately.

Signed-off-by: Ray Bejjani <7f525154e857f3d57a641a83dddc584f42addc6a@isovalent.com>

cilium/cilium,cilium/cilium,tgraf/cilium,michi-covalent/cilium,michi-covalent/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,tgraf/cilium,tgraf/cilium,cilium-team/cilium,michi-covalent/cilium,tgraf/cilium,cilium-team/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,cilium/cilium,tklauser/cilium,tgraf/cilium,tgraf/cilium,tklauser/cilium