Drop the os-svc-install -n -c options.

Updates os-svc-install so that we disallow the -n and -c options.

Also, corrects the optargs for -h so that it doesn't take a parameter.
And fix some variable bound issues that could occur if the script
was executed with invalid args.

Change-Id: I4eb26fe6793aa1ad19b1dddc63a5f399e17a8325
Closes-bug: #1285283