checkGooglePlay method
Checks a purchase Google Play returned: its product id and purchase
token (serverVerificationData in in_app_purchase). restored is
as for checkAppStore.
Implementation
Future<FFXPurchaseState> checkGooglePlay({
required String productId,
required String purchaseToken,
bool restored = false,
}) => _check({
'store': 'googlePlay',
'productId': productId,
'purchaseToken': purchaseToken,
if (restored) 'restored': true,
});