Fix header icon (#3910)

* fixes header change
* Update src/core/public/chrome/ui/header/header_help_menu.tsx
* fixes snapshots

Signed-off-by: Ashwin P Chandran <ashwinpc@amazon.com>

---------

Signed-off-by: Ashwin P Chandran <ashwinpc@amazon.com>
Co-authored-by: Josh Romero <rmerqg@amazon.com>
(cherry picked from commit 3cca088)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

src/core/public/chrome/ui/header/__snapshots__/header.test.tsx.snap

@@ -330,9 +330,8 @@ class HeaderHelpMenuUI extends Component<Props, State> {
         })}
         onClick={this.onMenuButtonClick}
       >
-        <EuiIcon type="questionInCircle" size="m" />
         <EuiIcon
-          type="help"
+          type="questionInCircle"
           size="m"
           title={intl.formatMessage({
             id: 'core.ui.chrome.headerGlobalNav.helpMenuButtonTitle',