test: Use timedatectl
test: Use timedatectl

Since it is the most portable way of controlling the clock.  (Except
that it doesn't shut down ntpd on Debian.)

Closes #3751
Reviewed-by: Dominik Perpeet <f7830b2723a5db4fc185058b06cfab4b89a38da9@redhat.com>

stefwalter/cockpit,michalskrivanek/cockpit,SotolitoLabs/cockpit,moraleslazaro/cockpit,Scribery/cockpit,Scribery/cockpit,garrett/cockpit,andreasn/cockpit,Scribery/cockpit,arilivigni/cockpit,larsu/cockpit,larskarlitski/cockpit,andreasn/cockpit,martinpitt/cockpit,cockpituous/cockpit,arilivigni/cockpit,cockpituous/cockpit,garrett/cockpit,michalskrivanek/cockpit,sgallagher/cockpit,sgallagher/cockpit,moraleslazaro/cockpit,arilivigni/cockpit,deryni/cockpit,matobet/cockpit,dperpeet/cockpit,petervo/cockpit,petervo/cockpit,dperpeet/cockpit,michalskrivanek/cockpit,moraleslazaro/cockpit,dperpeet/cockpit,xhad/cockpit,jscotka/cockpit,moraleslazaro/cockpit,Scribery/cockpit,SotolitoLabs/cockpit,matobet/cockpit,stefwalter/cockpit,mvollmer/cockpit,andreasn/cockpit,cockpituous/cockpit,cockpit-project/cockpit,deryni/cockpit,xhad/cockpit,deryni/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,Scribery/cockpit,larsu/cockpit,mareklibra/cockpit,xhad/cockpit,larskarlitski/cockpit,petervo/cockpit,petervo/cockpit,dperpeet/cockpit,vanloswang/cockpit,harishanand95/cockpit,xhad/cockpit,sgallagher/cockpit,martinpitt/cockpit,stefwalter/cockpit,xhad/cockpit,sgallagher/cockpit,larskarlitski/cockpit,jscotka/cockpit,xhad/cockpit,deryni/cockpit,vanloswang/cockpit,vanloswang/cockpit,mvollmer/cockpit,sgallagher/cockpit,dperpeet/cockpit,larsu/cockpit,petervo/cockpit,andreasn/cockpit,SotolitoLabs/cockpit,cockpit-project/cockpit,mareklibra/cockpit,harishanand95/cockpit,cockpituous/cockpit,stefwalter/cockpit,michalskrivanek/cockpit,garrett/cockpit,cockpituous/cockpit,mvollmer/cockpit,SotolitoLabs/cockpit,SotolitoLabs/cockpit,dperpeet/cockpit,xhad/cockpit,vanloswang/cockpit,martinpitt/cockpit,SotolitoLabs/cockpit,arilivigni/cockpit,andreasn/cockpit,arilivigni/cockpit,harishanand95/cockpit,dperpeet/cockpit,matobet/cockpit,stefwalter/cockpit,harishanand95/cockpit,michalskrivanek/cockpit,deryni/cockpit,deryni/cockpit,stefwalter/cockpit,Scribery/cockpit,vanloswang/cockpit,harishanand95/cockpit,moraleslazaro/cockpit,SotolitoLabs/cockpit,sgallagher/cockpit,larskarlitski/cockpit,moraleslazaro/cockpit,garrett/cockpit,garrett/cockpit,michalskrivanek/cockpit,mareklibra/cockpit,cockpit-project/cockpit,sgallagher/cockpit,arilivigni/cockpit,jscotka/cockpit,larsu/cockpit,michalskrivanek/cockpit,matobet/cockpit,moraleslazaro/cockpit,larsu/cockpit,mareklibra/cockpit,stefwalter/cockpit,larskarlitski/cockpit,andreasn/cockpit,harishanand95/cockpit,deryni/cockpit,Scribery/cockpit,mvollmer/cockpit,martinpitt/cockpit,vanloswang/cockpit,andreasn/cockpit,larskarlitski/cockpit,matobet/cockpit,petervo/cockpit,vanloswang/cockpit,matobet/cockpit,mareklibra/cockpit,larsu/cockpit,mareklibra/cockpit,jscotka/cockpit,martinpitt/cockpit,larskarlitski/cockpit,mvollmer/cockpit,arilivigni/cockpit,mareklibra/cockpit,cockpituous/cockpit,petervo/cockpit,jscotka/cockpit,harishanand95/cockpit,jscotka/cockpit