[Manual Backport 1.3] Add tooltip to help icon (#3626)

CHANGELOG.md

@@ -122,6 +122,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Temporary workaround for task-kill exceptions on Windows when it is passed a pid for a process that is already dead ([#2842](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2842))
 - [Build] Fixed "Last Access Time" not being set by `scanCopy` on Windows ([#2964](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2964))
 - Update `leaflet-vega` and fix its usage ([#3005](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/3005))
+- Add clarifying tooltips to header navigation ([#3573](https://github.com/opensearch-project/OpenSearch-Dashboards/issues/3573))
 
 ### 🚞 Infrastructure
 

src/core/public/chrome/ui/header/header.tsx

@@ -175,7 +175,13 @@ export function Header({
                   aria-controls={navId}
                   ref={toggleCollapsibleNavRef}
                 >
-                  <EuiIcon type="menu" size="m" />
+                  <EuiIcon
+                    type="menu"
+                    size="m"
+                    title={i18n.translate('core.ui.primaryNav.menu', {
+                      defaultMessage: 'Menu',
+                    })}
+                  />
                 </EuiHeaderSectionItemButton>
               </EuiHeaderSectionItem>
 

src/core/public/chrome/ui/header/header_help_menu.tsx

@@ -330,7 +330,15 @@ class HeaderHelpMenuUI extends Component<Props, State> {
         })}
         onClick={this.onMenuButtonClick}
       >
-        <EuiIcon type="help" size="m" />
+        <EuiIcon type="questionInCircle" size="m" />
+        <EuiIcon
+          type="help"
+          size="m"
+          title={intl.formatMessage({
+            id: 'core.ui.chrome.headerGlobalNav.helpMenuButtonTitle',
+            defaultMessage: 'Help',
+          })}
+        />
       </EuiHeaderSectionItemButton>
     );