android-ndk r10b

Previously the formula produced wrong directory structure. I've fixed it to be the same as when performing the following commands:
```
tar xf android-ndk32-r10b-darwin-x86_64.tar.bz2
tar xf android-ndk64-r10b-darwin-x86_64.tar.bz2
```
ndk32 is the main package for targeting Android 1.5 and up. It contains GCC and Clang toolchains for ARM, ARM-v7a, x86 and MIPS. ndk64 is supplemental package for targeting Android L Developer. It also contains toolchains for ARM-v8a, x86-64 and MIPS64 and GCC 4.9 which didn't fit into ndk32 because of file size limitation on server.