Bump stemcell to 3232.19 and remove alpha for 1.7.13
Bump stemcell to 3232.19 and remove alpha for 1.7.13

[#130391283]

pivotal-cf-experimental/ops-manager-example,pivotal-cf-experimental/ops-manager-example,pivotal-cf-experimental/ops-manager-example,pivotal-cf-experimental/ops-manager-example