DELIA-26033 : Getting the latest cronlist before updating RFC cron
DELIA-26033 : Getting the latest cronlist before updating RFC cron

Reason for change: RFC was using the initial cronlist populated by DCM for updating it cron, hence
                   the crons added from other scripts are overwritten
Test Procedure: Verify whether ping telemetry cron is present
Risks: Low
Signed-off-by: gtheres <Geethu_TheresK2@comcast.com>

Change-Id: I65ca8fa1a9fdd96e146e3d9e8415f2290efea3e4

rdkcmf/rdk-sysint