MDL-68525 behat: chrome/switches caps not allowed in Chrome > 81

Now we need to use extra_capabilities/chromeOptions/args instead

The former was deprecated long ago, it seems that Chrome 81 has
stopped accepting it. The later seems to be working at very least
since Chrome 76 (haven't gone further back).

lib/behat/classes/behat_config_util.php

@@ -637,14 +637,17 @@ protected function get_behat_profile($profile, $values) {
             if (!isset($values['capabilities'])) {
                 $values['capabilities'] = [];
             }
-            if (!isset($values['capabilities']['chrome'])) {
-                $values['capabilities']['chrome'] = [];
+            if (!isset($values['capabilities']['extra_capabilities'])) {
+                $values['capabilities']['extra_capabilities'] = [];
             }
-            if (!isset($values['capabilities']['chrome']['switches'])) {
-                $values['capabilities']['chrome']['switches'] = [];
+            if (!isset($values['capabilities']['extra_capabilities']['chromeOptions'])) {
+                $values['capabilities']['extra_capabilities']['chromeOptions'] = [];
             }
-            $values['capabilities']['chrome']['switches'][] = '--unlimited-storage';
-            $values['capabilities']['chrome']['switches'][] = '--disable-web-security';
+            if (!isset($values['capabilities']['extra_capabilities']['chromeOptions']['args'])) {
+                $values['capabilities']['extra_capabilities']['chromeOptions']['args'] = [];
+            }
+            $values['capabilities']['extra_capabilities']['chromeOptions']['args'][] = '--unlimited-storage';
+            $values['capabilities']['extra_capabilities']['chromeOptions']['args'][] = '--disable-web-security';
 
             // If the mobile app is enabled, check its version and add appropriate tags.
             if ($mobiletags = $this->get_mobile_version_tags()) {