[8.14] [Security Solution][Alert details] - remove old flyout unneces…

…sary z-index change (#181480) (#181784)

# Backport

This will backport the following commits from `main` to `8.14`:
- [[Security Solution][Alert details] - remove old flyout unnecessary
z-index change (#181480)](#181480)

<!--- Backport version: 9.4.3 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Philippe
Oberti","email":"philippe.oberti@elastic.co"},"sourceCommit":{"committedDate":"2024-04-25T21:39:50Z","message":"[Security
Solution][Alert details] - remove old flyout unnecessary z-index change
(#181480)","sha":"84e3ea51a8f5b8ead0abfcf40016c02d0b3c3ab2","branchLabelMapping":{"^v8.15.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["release_note:skip","Team:Threat
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Solution][Alert details] - remove old flyout unnecessary z-index
change","number":181480,"url":"#181480
Solution][Alert details] - remove old flyout unnecessary z-index change
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Solution][Alert details] - remove old flyout unnecessary z-index change
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BACKPORT-->

Co-authored-by: Philippe Oberti <philippe.oberti@elastic.co>

x-pack/plugins/security_solution/public/timelines/components/side_panel/index.tsx

@@ -12,7 +12,6 @@ import { EuiFlyout } from '@elastic/eui';
 
 import type { EntityType } from '@kbn/timelines-plugin/common';
 import { dataTableActions, dataTableSelectors } from '@kbn/securitysolution-data-table';
-import styled from 'styled-components';
 import { getScopedActions, isInTableScope, isTimelineScope } from '../../../helpers';
 import { timelineSelectors } from '../../store';
 import { timelineDefaults } from '../../store/defaults';
@@ -36,11 +35,6 @@ interface DetailsPanelProps {
   isReadOnly?: boolean;
 }
 
-// hack to to get around the fact that this flyout causes issue with timeline modal z-index
-const StyleEuiFlyout = styled(EuiFlyout)`
-  z-index: 1002;
-`;
-
 /**
  * This panel is used in both the main timeline as well as the flyouts on the host, detection, cases, and network pages.
  * To prevent duplication the `isFlyoutView` prop is passed to determine the layout that should be used
@@ -172,15 +166,15 @@ export const DetailsPanel = React.memo(
     }
 
     return isFlyoutView ? (
-      <StyleEuiFlyout
+      <EuiFlyout
         data-test-subj="timeline:details-panel:flyout"
         size={panelSize}
         onClose={closePanel}
         ownFocus={false}
         key={flyoutUniqueKey}
       >
         {visiblePanel}
-      </StyleEuiFlyout>
+      </EuiFlyout>
     ) : (
       visiblePanel
     );

x-pack/test/security_solution_cypress/cypress/e2e/investigations/timelines/unified_components/query_tab.cy.ts

@@ -47,6 +47,7 @@ describe(
       createNewTimeline();
       executeTimelineSearch('*');
     });
+
     it('should be able to add/remove columns correctly', () => {
       cy.get(GET_UNIFIED_DATA_GRID_CELL_HEADER('agent.type')).should('not.exist');
       addFieldToTable('agent.type');
@@ -55,8 +56,9 @@ describe(
       cy.get(GET_DISCOVER_DATA_GRID_CELL_HEADER('agent.type')).should('not.exist');
     });
 
+    // these tests are skipped until we implement the expandable flyout in the unified table for timeline
     context('flyout', () => {
-      it('should be able to open/close details details/host/user flyout', () => {
+      it.skip('should be able to open/close details details/host/user flyout', () => {
         cy.log('Event Details Flyout');
         openEventDetailsFlyout(0);
         cy.get(TIMELINE_DETAILS_FLYOUT).should('be.visible');