Script fix for test_bmc_network_conf.robot file

Changes:
- Added sleep 3 sec Configure Static Name Servers keyword
- Added Wait Until Keyword Succeeds.
- Created a new keyword CLI Get and Verify Name Servers in
  bmc_network_utils.robot.

Tested:
- Ran redfish/managers/test_bmc_network_conf.robot successfully.

Change-Id: Ieec8b1d65e374da73adcccebbdc310e8ba5703bf
Signed-off-by: KothaiSrini <kothais@ami.com>
diff --git a/lib/bmc_network_utils.robot b/lib/bmc_network_utils.robot
index 698809c..772b892 100644
--- a/lib/bmc_network_utils.robot
+++ b/lib/bmc_network_utils.robot
@@ -418,6 +418,21 @@
 
     [Return]  ${nameservers}
 
+CLI Get and Verify Name Servers
+    [Documentation]    Get and Verify the nameserver IPs from /etc/resolv.conf and compare with redfish nameserver.
+    [Arguments]     ${static_name_servers}
+    ...  ${valid_status_codes}=${HTTP_OK}
+
+    # Description of Argument(s):
+    # static_name_servers:   Address for static name server
+
+    ${cli_nameservers}=  CLI Get Nameservers
+    ${cmd_status}=  Run Keyword And Return Status
+    ...  List Should Contain Sub List  ${cli_nameservers}  ${static_name_servers}
+
+    Run Keyword If  '${valid_status_codes}' == '${HTTP_OK}'
+    ...  Should Be True  ${cmd_status}
+    ...  ELSE  Should Be True  ${cmd_status}
 
 Get Network Configuration
     [Documentation]  Get network configuration.