This does two things. First, it aligns the brew formula name
(AndroidNdk) with the brew file name (android-ndk.rb). Second, it
makes sure that we actually find the android-ndk.rb file. I think
|mach bootstrap| always worked, due to a felicity where the working
directory always contained android-ndk.rb; but |python bootstrap.py|
failed because android-ndk.rb was downloaded to a temporary location
that was not included in the |brew install| command.
c09b1243eb