Refactoring ResourceAssignmentUtils

Changing isNull condition to isNullOrEmpty to make sure Empty value doesn't get assigned to resource

Issue-ID: CCSDK-1748
Signed-off-by: Singal, Kapil (ks220y) <ks220y@att.com>
Change-Id: I0744537c7ddec80f20ffd7e6545b947439f63743
9 files changed