解決Service Intent must be explicit

更改舊android專案升到api 28時，一直跳出Service Intent must be explicit，找半天解答，如：Service Intent must be explicit的解决方案或【完美解决系列】Service Intent must be explicit，都太複雜，後來看到Google In-App billing, IllegalArgumentException: Service Intent must be explicit, after upgrading to Android L Dev Preview，才了解重點在Intent要設定Package字串，如，我在用的是"com.android.vending.billing.MarketBillingService.BIND"，就設定intent.setPackage("com.android.vending")，這樣就OK了

參考網址：

Google In-App billing, IllegalArgumentException: Service Intent must be explicit, after upgrading to Android L Dev Preview