Use correct z-index for timeline global footer (#111492)

x-pack/plugins/security_solution/public/app/home/template_wrapper/index.tsx

@@ -42,7 +42,6 @@ const StyledKibanaPageTemplate = styled(KibanaPageTemplate)<{
     transform: ${(
       { $isShowingTimelineOverlay } // Since the bottom bar wraps the whole overlay now, need to override any transforms when it is open
     ) => ($isShowingTimelineOverlay ? 'none' : 'translateY(calc(100% - 50px))')};
-    z-index: ${({ theme }) => theme.eui.euiZLevel8};
 
     .${IS_DRAGGING_CLASS_NAME} & {
       // When a drag is in process the bottom flyout should slide up to allow a drop