fix regression bug: only enable alert but not monitoring not deploy prometheus operator
fix regression bug: only enable alert but not monitoring not deploy prometheus
operator

Problem:
could not only enable alert because after refactor monitoring deploy
operator logic is updated, but related deploy alertmanager code not update completely

Solution:
update deploy alertmanager logic

Issue:
https://github.com/rancher/rancher/issues/18010

rancherio/rancher,rancher/rancher,cjellick/rancher,rancher/rancher,cjellick/rancher,rancher/rancher,rancherio/rancher,cjellick/rancher,rancher/rancher