Don't hardcode privilege escalation prompts if they're all of the same format.

Just create them all from supported privilege escalation types.

awx/main/constants.py

@@ -1,5 +1,14 @@
 # Copyright (c) 2015 Ansible, Inc.
 # All Rights Reserved.
 
+from django.utils.translation import ugettext_lazy as _
+
 CLOUD_PROVIDERS = ('azure', 'azure_rm', 'ec2', 'gce', 'rax', 'vmware', 'openstack', 'satellite6', 'cloudforms')
 SCHEDULEABLE_PROVIDERS = CLOUD_PROVIDERS + ('custom', 'scm',)
+PRIVILEGE_ESCALATION_METHODS = [
+                ('sudo', _('Sudo')),
+                ('su', _('Su')),
+                ('pbrun', _('Pbrun')),
+                ('pfexec', _('Pfexec')),
+                ('dzdo', _('DZDO')),
+                ('pmrun', _('Pmrun'))]