Added XPATH variable and correction changes

Changes:

    - Added XPATH and variables for Network, Error logs, inventory and LED's, Firmware and  Power headings.
    - Changed XPATH names as per gui/data/gui_variables.py

Tested:
    - Ran successfully gui/data/gui_variables.py
    - Ran successfully gui/gui_test/gui_header/test_gui_header.robot
    - Ran successfully gui/gui_test/overview_menu/test_overview_menu.robot

Change-Id: I84f7fd7a8c9862a0e770e2b8d11d503b7bbc82eb
Signed-off-by: rramyasr-in <rramyasr@in.ibm.com>
diff --git a/gui/gui_test/overview_menu/test_overview_menu.robot b/gui/gui_test/overview_menu/test_overview_menu.robot
index 7b4e790..73fc570 100644
--- a/gui/gui_test/overview_menu/test_overview_menu.robot
+++ b/gui/gui_test/overview_menu/test_overview_menu.robot
@@ -86,7 +86,7 @@
     [Tags]  Verify_Edit_Network_Setting_Button
 
     Click Element  ${xpath_edit_network_settings_button}
-    Wait Until Page Contains Element  ${xpath_network_page_header}
+    Wait Until Page Contains Element  ${xpath_network_heading}
 
 
 Verify Event Under High Priority Events Section