GUI:Replaced with 'Wait Until Element Is Visible' step.

Changes:
    - In gui/gui_test/security_and_access_menu/test_user_management_sub_menu.robot
    - Replaced 'Wait Until Page Contains Element' keyword with 'Wait Until Element Is Visible'.

Tested: -Ran above test case from sandbox successfully
Change-Id: I307a6fc1193a5ced78aeea72b8f6009baa862508
Signed-off-by: Nandish-Matti <nandish.matti@ibm.com>
diff --git a/gui/gui_test/operations_menu/test_server_power_operations_sub_menu.robot b/gui/gui_test/operations_menu/test_server_power_operations_sub_menu.robot
index d10f204..c8ae12e 100644
--- a/gui/gui_test/operations_menu/test_server_power_operations_sub_menu.robot
+++ b/gui/gui_test/operations_menu/test_server_power_operations_sub_menu.robot
@@ -141,7 +141,7 @@
     ...  AND  Navigate to Server Power Operation Page
 
     Click Element  ${xpath_reboot_button}
-    Wait Until Page Contains Element  ${xpath_confirm_button}  timeout=10
+    Wait Until Element Is Visible  ${xpath_confirm_button}  timeout=10
     Click Element  ${xpath_confirm_button}
     Wait Until Keyword Succeeds  2 min  1 sec  Is Server Status Off
     Click Element  ${xpath_refresh_button}