Use CentOS cmd while syncing time on bootstrap

If node in bootstrap mode we should use 'ntpd' as
daemon name wile synchronizing time, even if Ubuntu
is selected as OS, because bootsrap image is based
on CentOS.

Change-Id: Ic2e86306844709b1794f94e3612306384a2aaaa9
Closes-bug: #1353455
Merge "Use CentOS cmd while syncing time on bootstrap"