GUI: Updated xpath and verify disable status of buttons.

Changes:
	- updated xpath for 'Add File' button.
        - Verify the disable status of the buttons.

Tested:
	-Ran above test case from sandbox successfully.

Change-Id: Id753ded80aa19c1007d2f334f73b816f0b19961c
Signed-off-by: Nandish-Matti <nandish.matti@ibm.com>
diff --git a/gui/gui_test/operations_menu/test_firmware_sub_menu.robot b/gui/gui_test/operations_menu/test_firmware_sub_menu.robot
index 208d662..eee85a2 100644
--- a/gui/gui_test/operations_menu/test_firmware_sub_menu.robot
+++ b/gui/gui_test/operations_menu/test_firmware_sub_menu.robot
@@ -10,7 +10,7 @@
 *** Variables ***
 
 ${xpath_firmware_heading}                //h1[text()="Firmware"]
-${xpath_add_file_button}                 //*[contains(text(),"Add file")]
+${xpath_add_file_button}                 //*[@id='image-file']
 ${xpath_start_update_button}             //*[@data-test-id="firmware-button-startUpdate"]
 
 
@@ -58,8 +58,8 @@
 
     Redfish Power On  stack_mode=skip
 
-    Page Does Not Contain Element  ${xpath_add_file}
-    Page Does Not Contain Element  ${xpath_start_update}
+    Element Should Be Disabled  ${xpath_add_file_button}
+    Element Should Be Disabled  ${xpath_start_update_button}
 
 
 *** Keywords ***