Why doesn't Android have tombstone mechanism? Is it an Apple patent?

Android has a SavedInstanceState to save the information of some killed components, but it takes several seconds to render the SavedInstanceState into an interactive interface (depending on the complexity of the interface). In a sense, the recycling of WP is similar. However, in fact, this function is rarely realized in China. Android is divided into domestic Android and foreign Android. Like Apple, Android with Google and Song GCM services abroad has software push notifications to access Google and Song servers, and Google and Song services push message notifications to mobile phones (Android unified push platform GCM). Foreign Android software doesn't need to hang in the background, receiving messages like Apple's ios system. To realize the tombstone mechanism, we must first solve the problem of unified push. There is no GCM service in the National Day Android system.