Summary:
Currently, it's hard to find out that it's very easy to use android toasts. The example is very complex and hard to grasp for a beginner. So, I propose to add an easy to understand example.
I'm sure the syntax of this PR is not really correct, it's just a start to show the kind of thing I propose.
Closes https://github.com/facebook/react-native/pull/9859
Differential Revision: D3886274
Pulled By: donyu
fbshipit-source-id: 15e693f5ddb1efea0fc6b7accfa688fd5f99a100
644b93dc11