Wait for ping succeed before trying SSH in create|get_timestamp methods

Change-Id: Ieece88f5e8cfa80fe6d12720602066dffa5f8d9a
Related-Prod: PRODX-14386
(cherry picked from commit 5e522e625386c39361e5370e11e749071285b5e9)
(cherry picked from commit b5cd7d94276bf6b6785b04c7bbccbe231bb68d2d)
1 file changed