Add sync time to wait for file to write to ALT

Change-Id: I089954a23c107ee3ddc4d71586d4ca127ab7e3ab
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/redfish/extended/test_bmc_file_mirroring.robot b/redfish/extended/test_bmc_file_mirroring.robot
index 8bc4999..5870740 100755
--- a/redfish/extended/test_bmc_file_mirroring.robot
+++ b/redfish/extended/test_bmc_file_mirroring.robot
@@ -46,6 +46,9 @@
     # Example output from "ls /media/alt/var/persist/etc/":
     # group  group-  gshadow  gshadow-  hostname  machine-id  ssl  systemd
 
+    # Wait time for syncing to ALT side.
+    Sleep  2
+
     ${curr_hostname}  ${stderr}  ${rc}=  BMC Execute Command
     ...  cat /media/alt/var/persist/etc/hostname