Summary:
> Explain the **motivation** for making this change. What existing problem does the pull request solve?
There's no longer a seaprate page for Android setup instructions, it just redirects to the getting started page, where you have to navigate futher.
**Test plan (required)**
None.
Closes https://github.com/facebook/react-native/pull/10524
Differential Revision: D4069696
Pulled By: lacker
fbshipit-source-id: 67f6450f550cbbf446476ea824a6915125e823ba