Managers ID : Introduced variable to declare Managers ID in resource.robot and updated all the scripts in openbmc-test-automation

Changes:
    - Introduced ${MANAGER_ID} variable in resource.robot
    - Replaced all the Managers/bmc to Managers/${MANAGER_ID} across all the scripts
    - Also in data/variables.py updated chassis id for the few redfish uri.

Tested:
     - Ran All The Scripts Successfully

Change-Id: Iff3673aae27657e0799dec5cb94c1651a0cd5d18
Signed-off-by: ganesanb <ganesanb@ami.com>
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/lib/bmc_redfish_utils.py b/lib/bmc_redfish_utils.py
index e93eee3..e240d94 100644
--- a/lib/bmc_redfish_utils.py
+++ b/lib/bmc_redfish_utils.py
@@ -297,7 +297,7 @@
                 # required in enumeration.
                 # Example: '/redfish/v1/JsonSchemas/' and sub resources.
                 #          '/redfish/v1/SessionService'
-                #          '/redfish/v1/Managers/bmc#/Oem'
+                #          '/redfish/v1/Managers/${MANAGER_ID}#/Oem'
                 if (
                     ("JsonSchemas" in resource)
                     or ("SessionService" in resource)