[Privacy Sandbox] Fix "policy" setting

Add is_int check before getting the default cookie policy to only grab
the value when it exists and fix a badVariantAccess.

Bug: 1167622
Change-Id: I0733a1c61233aa702cc40698b9d06c2878222ec6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2631501Reviewed-by: Martin Šrámek <msramek@chromium.org>
Commit-Queue: Sean Harrison <harrisonsean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844499}

components/content_settings/core/browser/cookie_settings_policy_handler.cc

@@ -41,7 +41,7 @@ void CookieSettingsPolicyHandler::ApplyPolicySettings(
   // privacy sandbox if it is set to BLOCK.
   const base::Value* default_cookie_setting =
       policies.GetValue(policy::key::kDefaultCookiesSetting);
-  if (default_cookie_setting &&
+  if (default_cookie_setting && default_cookie_setting->is_int() &&
       static_cast<ContentSetting>(default_cookie_setting->GetInt()) ==
           CONTENT_SETTING_BLOCK) {
     prefs->SetBoolean(prefs::kPrivacySandboxApisEnabled, false);