Fix 'cannot read property' error from ExPlat (https://github.com/woocommerce/woocommerce-admin/pull/7600)

* Change option value path

* Try wcSettings.preloadSettings.general first

* Add changelog

plugins/woocommerce-admin/packages/explat/CHANGELOG.md

@@ -1,3 +1,7 @@
+# Unreleased
+
+- Fix an error when getting woocommerce_default_country value. #7600
+- Attempts to get the woocommerce_default_country value in wcSettings.preloadSettings.general first for the backward compatibility #7600
 # 1.1.3 
 
 - Retry fix for missing build-module folder

plugins/woocommerce-admin/packages/explat/src/assignment.ts

@@ -22,8 +22,10 @@ export const fetchExperimentAssignment = async ( {
 		experiment_name: experimentName,
 		anon_id: anonId ?? undefined,
 		woo_country_code:
-			window.wcSettings.preloadSettings.general
-				.woocommerce_default_country,
+			window.wcSettings?.preloadSettings?.general
+				?.woocommerce_default_country ||
+			window.wcSettings?.admin?.preloadSettings?.general
+				?.woocommerce_default_country,
 	} );
 
 	const response = await window.fetch(

plugins/woocommerce-admin/packages/explat/src/utils.ts

@@ -10,10 +10,15 @@ interface generalSettings {
 interface preloadSettings {
 	general: generalSettings;
 }
-
-interface wcSettings {
+interface admin {
 	preloadSettings: preloadSettings;
 }
+
+interface wcSettings {
+	admin: admin;
+	preloadSettings: preloadSettings;
+}
+
 declare global {
 	interface Window {
 		wcSettings: wcSettings;