Fix icon path in tutorial introduction (elastic#49684)

Some icons are included as SVG files with relative paths to their
location. Add the base path so these files are correctly displayed when
Kibana is not running from the root path.

src/legacy/core_plugins/kibana/public/home/np_ready/components/tutorial/tutorial.js

@@ -363,6 +363,11 @@ class TutorialUi extends React.Component {
         );
       }
 
+      let icon = this.state.tutorial.euiIconType;
+      if (icon && icon.includes('/')) {
+        icon = this.props.addBasePath(icon);
+      }
+
       const instructions = this.getInstructions();
       content = (
         <div>
@@ -371,7 +376,7 @@ class TutorialUi extends React.Component {
             description={this.props.replaceTemplateStrings(this.state.tutorial.longDescription)}
             previewUrl={previewUrl}
             exportedFieldsUrl={exportedFieldsUrl}
-            iconType={this.state.tutorial.euiIconType}
+            iconType={icon}
             isBeta={this.state.tutorial.isBeta}
           />
 

src/legacy/core_plugins/kibana/public/home/np_ready/components/tutorial_directory.js

@@ -129,7 +129,7 @@ class TutorialDirectoryUi extends React.Component {
     let tutorialCards = tutorialConfigs.map(tutorialConfig => {
       // add base path to SVG based icons
       let icon = tutorialConfig.euiIconType;
-      if (icon != null && icon.includes('/')) {
+      if (icon && icon.includes('/')) {
         icon = this.props.addBasePath(icon);
       }