Fixed to show gtl buttons on sub-list views for a Tenant.

- Removed unused 'no_toggle_dash_buttons' variable from top of the view file.
- Added cloud_tenant to list of screens that need to render gtl buttons, moved the check into helper to determine whether to render gtl_view_tb or not

https://bugzilla.redhat.com/show_bug.cgi?id=1140357

@dclarizio please review/test.
@h-kataria Can you make this a constant right above this method so it's easier to read and see which layouts are in the list?  Thx, Dan