Update Android NDK to r13b

[mickele]

The information about the releases can be found at https://github.com/android-ndk/ndk/wiki

[viktorbenei]

Awesome, thank you very much!

Just one note, you used r13b which I guess was the beta, but the current version of the NDK is r13 (https://dl.google.com/android/repository/android-ndk-r13-linux-x86_64.zip) - see: https://developer.android.com/ndk/downloads/index.html

Am I right that r13 is newer than r13b?

[mickele]

I was confused about this as well, but now I'm pretty sure r13b is newer than r13. It's not clear in its official docs but I believe that because of two things:

1. Android Studio 2.2 will download the r13b from the SDK Updater, and I'm using all stable channels. It will get the list from https://dl.google.com/android/repository/repository2-1.xml (look for "ndk-bundle").
2. I believe the NDK downloads website is just outdated (as usual), in this repository: https://github.com/android-ndk/ndk/wiki they show that the letters are actually incremental for patch-releases.

But to be honest I don't think there's much difference in both version, so feel free to change to the r13.

[viktorbenei]

All right, I guess it's better to stick with the version used by Android Studio ;)

Thanks for the PR! :)